Page 1 By KWANG YANG Motor Co., Ltd. First Edition, Dec 2006 All rights reserved. Any reproduction or unauthorized use without the written permission of KWANG YANG Motor Co., Ltd. is expressly prohibited. T100LA0975...
Page 2: Table Of Contents
The information and contents included in this manual may be different from the vehicle in case specifications are changed. KYMCO reserves the right to make changes at any time without notice and without incurring any obligation. KWANG YANG MOTOR CO., LTD.
Page 3: General Information
. GENERAL INFORMATION __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ GENERAL INFORMATION __________________________________________________________________________________ SERIAL NUMBER---------------------------------------------------------- 1- 1 SPECIFICATIONS ---------------------------------------------------------- 1- 2 SERVICE PRECAUTIONS ------------------------------------------------ 1- 6 TORQUE VALUES --------------------------------------------------------- 1-14 SPECIAL TOOLS ----------------------------------------------------------- 1-16 LUBRICATION POINTS -------------------------------------------------- 1-17 CABLE & HARNESS ROUTING ---------------------------------------- 1-20 WIRING DIAGRAMS ------------------------------------------------------ 1-23 TROUBLESHOOTING----------------------------------------------------- 1-28...
Page 4: General Information
. GENERAL INFORMATION SERIAL NUMBER Location of Frame Serial Number Location of Engine Serial Number Location of Engine Serial Number (50cc-2T) (90cc/70cc/50cc-4T)
Page 5: Specifications
. GENERAL INFORMATION SPECIFICATIONS Mongoose 90/MXER 90R Air cleaner type Sponge Model No. LA20 5.5 L (12.1 lmp gal, Overall length 1430 mm (57.2 in) Fuel capacity 1.45 US gal) Overall width 905 mm (36.2 in) Type Overall height 910 mm (36.4 in) Wheel base 965 mm (38.6 in)
Page 6 . GENERAL INFORMATION Mongoose 70/MXER 70R Model No. LA15 Air cleaner type Sponge 5.5 L (12.1 lmp gal, Overall length 1415 mm (56.6 in) Fuel capacity 1.45 US gal) Overall width 880 mm (35.2 in) Type Overall height 910 mm (36.4 in) Main jet No.
Page 7 . GENERAL INFORMATION Mongoose 50-4T /MXER 50R-4T Model No. LB10 Air cleaner type Sponge 5.5 L (12.1 lmp gal, Overall length 1430 mm (58 in) Fuel capacity 1.45 US gal) Overall width 870 mm (34.8 in) Type Overall height 900 mm (37.8 in) Main jet No.
Page 8 . GENERAL INFORMATION Mongoose 50-2T /MXER 50R-2T Air cleaner type & No Sponge Name & Model No. LA10 5.5 L (12.1 lmp gal, 1.45 Overall length 1385 mm (55.4 in) Fuel capacity US gal) Overall width 875 mm (35 in) Type Overall height 890 mm (35.6 in)
Page 9: Service Precautions
. GENERAL INFORMATION SERVICE PRECAUTIONS Make sure to install new gaskets, O-rings, circlips, cotter pins, etc. when reassembling. When tightening bolts or nuts, begin with larger-diameter to smaller ones at several times, and tighten to the specified torque diagonally. Use genuine parts and lubricants. When servicing the motorcycle, be sure to use special tools for removal and installation.
Page 10 . GENERAL INFORMATION Apply or add designated greases and lubricants to the specified lubrication points. After reassembly, check all parts for proper tightening and operation. When two persons work together, pay attention to the mutual working safety. Disconnect the battery negative (-) terminal before operation.
Page 11 . GENERAL INFORMATION If the fuse is burned out, find the cause Confirm and repair it. Replace it with a new one Capacity according to the specified capacity. After operation, terminal caps shall be installed securely. When taking out the connector, the lock on the connector shall be released before operation.
Page 12 . GENERAL INFORMATION The connector shall be inserted completely. Snapping! If the double connector has a lock, lock it at the correct position. Check if there is any loose wire. Before connecting a terminal, check for damaged terminal cover or loose negative terminal.
Page 13 . GENERAL INFORMATION After clamping, check each wire to make sure it is secure. Do not squeeze wires against the weld or its clamp. After clamping, check each harness to make sure that it is not interfering with any moving or sliding parts. When fixing the wire harnesses, do not make it contact the parts which will No Contact !
Page 14 . GENERAL INFORMATION Route harnesses so they are neither pulled tight nor have excessive slack. Do not pull too tight! Protect wires and harnesses with electrical tape or tube if they contact a sharp edge or corner. When rubber protecting cover is used to protect the wire harnesses, it shall be installed securely.
Page 15 . GENERAL INFORMATION After routing, check that the wire harnesses are not twisted or kinked. Wire harnesses routed along with handlebar should not be pulled tight, have excessive slack or interfere with adjacent or surrounding parts in all steering positions. When a testing device is used, make sure to understand the operating methods Do you understand...
Page 16 . GENERAL INFORMATION Symbols: The following symbols represent the servicing methods and cautions included in this service manual. : Apply engine oil to the specified points. (Use designated engine oil for lubrication.) Engine Oil : Apply grease for lubrication. Grease : Transmission Gear Oil (90#) Gear Oil...
Page 17: Torque Values
. GENERAL INFORMATION TORQUE VALUES STANDARD TORQUE VALUES Torque Torque Item Item N•m (kgf•m, lbf•ft) N•m (kgf•m, lbf•ft) 5mm bolt and nut 5(0.5, 4) 4mm screw 3 (0.3, 2) 6mm bolt and nut 10 (1, 7) 4 (0.4, 3) 5mm screw 8mm bolt and nut 22 (2.2, 16) 9 (0.9, 6.5)
Page 18 . GENERAL INFORMATION ENGINE (50cc-2T) Torque Thread dia. Item Q‘ty Remarks N•m (kgf•m, (mm) lbf•ft) Cylinder head bolt 10 (1, 7) Clutch drive plate nut 55 (5.5, 40) Drive face nut 40 (4, 29) Clutch outer nut 40 (4, 29) ACG flywheel nut 40 (4, 29) Mission fill bolt...
Page 19: Special Tools
. GENERAL INFORMATION SPECIAL TOOLS 90cc/70cc/50cc-4T Remarks Ref. Page Tool Name Tool No. Clutch spring compressor A120E00034 Bearing puller A120E00037 Valve spring compressor A120E00040 Oil seal & bearing installer A120E00014 Tappet adjuster A120E00012 Long socket wrench A120E00015 Start clutch puller A120E00006 Flywheel puller A120E00001...
Page 20: Lubrication Points
. GENERAL INFORMATION LUBRICATION POINTS ENGINE (90cc/70/50-4T) Lubrication Points Lubricant •Genuine KYMCO Engine Oil (SAE15W-40) Valve guide/valve stem movable part •API SG Engine Oil Cam lobes Valve rocker arm friction surface Cam chain Cylinder lock bolt and nut Piston surroundings and piston ring grooves...
Page 21 . GENERAL INFORMATION FRAME The following is the lubrication points for the frame. Use general purpose grease for parts not listed. Apply clean engine oil or grease to cables and movable parts not specified. This will avoid abnormal noise and rise the durability of the ATV. Throttle Cable Steering knuckle Steering knuckle...
Page 22 . GENERAL INFORMATION Rear Swing Arm Axle Driven Sprocket Rear Axle Hub Collar/Oil Seal/Bearing 1-19...
Page 23: Cable & Harness Routing
. GENERAL INFORMATION CABLE & HARNESS ROUTING Throttle Cable Rear Brake Cable/Fluid Hose Rear Stop Switch Wire Kill Switch (Safety) Handlebar Switch Wire Harness Wire Front Brake Cable Rear Stop Switch Wire Front Stop Switch Wire Pilot Leads Kill Switch (Safety) (50cc-2T) Ignition Switch Coupler Handlebar Switch Coupler...
Page 24 . GENERAL INFORMATION Oil Level Switch Wire Starter Motor Wire (50cc-2T) Ignition Coil Ignition Coil Wire Oil Outlet Tube (50cc-2T) A.C.G. Wire 1-21...
Page 25 . GENERAL INFORMATION Throttle Cable Autobystarter Wire Fuel Tube Resistor Air Inlet Hose Harness Wire Battery Negative (-) Oil Pump Control Cable (50cc-2T) Battery Positive (+) Ignition Coil Wire Taillight Coupler Rear Brake Cable/Fluid Hose 1-22...
Page 26: Wiring Diagrams
. GENERAL INFORMATION WIRING DIAGRAMS Mongoose 90/MXER 90R/Mongoose 50-4T OFF ROAD 1-23...
Page 27 . GENERAL INFORMATION MXER 90R ON ROAD 1-24...
Page 28 . GENERAL INFORMATION Mongoose 70 1-25...
Page 29 . GENERAL INFORMATION Mongoose 50-2T/MXER 50R-2T OFF ROAD 1-26...
Page 30 . GENERAL INFORMATION MXER 50R-2T ON ROAD 1-27...
Page 31: Troubleshooting
. GENERAL INFORMATION TROUBLESHOOTING ENGINE WILL NOT START OR IS HARD TO START Inspection/Adjustment Probable Cause Symptom Check if fuel reaches carburetor by loosening drain screw Empty fuel tank Clogged fuel line between fuel tank and carburetor Clogged float oil passage Fuel reaches Fuel does not Clogged fuel tank cap breather...
Page 32 . GENERAL INFORMATION ENGINE LACKS POWER Inspection/Adjustment Probable Cause Symptom Start engine and accelerate lightly for observation Clogged air cleaner Restricted fuel flow Engine speed Engine speed does not Clogged fuel tank cap breather hole increase sufficiently increases Clogged exhaust muffler Carburetor fuel level too low Check ignition timing (using a timing light)
Page 33 . GENERAL INFORMATION POOR PERFORMANCE (ESPECIALLY AT IDLE AND LOW SPEEDS) Inspection/Adjustment Symptom Probable Cause Check ignition timing Faulty ignition unit Incorrect timing Correct timing Faulty pulser coil Check carburetor air screw adjustment Mixture too rich (turn screw Correctly adjusted Incorrectly adjusted out) Mixture too lean (turn screw in)
Page 34 . GENERAL INFORMATION POOR PERFORMANCE (AT HIGH SPEED) Inspection/Adjustment Symptom Probable Cause Check ignition timing Faulty CDI unit Correct timing Incorrect timing Faulty pulser coil Check valve clearance Improperly adjusted valve Correctly adjusted Incorrectly adjusted clearance Worn valve seat Check fuel pump for fuel supply Empty fuel tank Clogged fuel tube or filter...
Page 35 . GENERAL INFORMATION POOR CHARGING (BATTERY OVER DISCHARGING OR OVERCHARGING) Undercharging Inspection/Adjustment Symptom Probable Cause Start engine and test limit voltage of battery terminals Dead battery Voltage does not Normal voltage increase Faulty battery Measure resistance between AC generator coil terminals Faulty A.C.
Page 36 . GENERAL INFORMATION NO SPARK AT SPARK PLUG Inspection/Adjustment Symptom Probable Cause Replace with a new spark plug and inspect again Good spark Weak or no spark Faulty spark plug Check spark plug cap and high-tension wire for looseness Not loose Loose Loose spark plug cap Check CDI unit coupler...
Page 37: Frame Covers/Exhaust Muffler
. FRAME COVERS/EXHAUST MUFFLER __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ FRAME COVERS/EXHAUST MUFFLER __________________________________________________________________________________ SERVICE INFORMATION------------------------------------------------ 2- 2 FRAME COVERS ----------------------------------------------------------- 2- 3 EXHAUST MUFFLER REMOVAL-------------------------------------- 2- 7 TAILLIGHT BULB --------------------------------------------------------- 2- 8...
Page 38: Frame Covers/Exhaust Muffler
. FRAME COVERS/EXHAUST MUFFLER...
Page 39: Service Information
. FRAME COVERS/EXHAUST MUFFLER SERVICE INFORMATION GENERAL INSTRUCTIONS • When removing frame covers, use special care not to pull them by force because the cover joint claws may be damaged. • Make sure to route cables and harnesses according to the Cable & Harness Routing. TORQUE VALUES Exhaust muffler lock bolt 35 N-m (3.5 kgf-m, 25 lbf-ft)
Page 40: Frame Covers
. FRAME COVERS/EXHAUST MUFFLER Bolts FRAME COVERS HANDLEBAR COVER REMOVAL Remove the two screws attaching the handlebar cover. Disconnect the oil level indicator leads. Remove the handlebar cover. INSTALLATION Reverse the “HANDLEBAR COVER REMOVAL” procedures. Handlebar Cover Seat Lock Lever SEAT REMOVAL To remove the seat, pull upward the seat lock lever and pull up the seat at the rear.
Page 41 . FRAME COVERS/EXHAUST MUFFLER Front Brake Cables Disconnect the front brake cables. Disconnect the remote stop switch and front brake stop switch leads. Remote Engine Stop Front Brake Stop Switch Leads Switch Leads Screws Throttle Cable Remove the two screws and speed limiter cover.
Page 42 . FRAME COVERS/EXHAUST MUFFLER Screws Screws FRONT FENDER REMOVAL Remove the seat. (See page 2-3) Remove the handlebar. (See page 2-3) Remove the six screws and nuts attaching the front fender and right/left foot boards. Screws Screws Remove the four screws and two nuts attaching the front fender and rear fender at the right/left side.
Page 43 . FRAME COVERS/EXHAUST MUFFLER INSTALLATION Reverse the “FRONT FENDER REMOVAL” procedures. ＊ After remove, be sure to tighten the fuel filler cap. Starter Relay Ignition Unit REAR FENDER REMOVAL Remove the front fender. (See page 2-5) Remove the battery. (See chapter 14) Remove the starter relay and CDI unit.
Page 44: Exhaust Muffler Removal
. FRAME COVERS/EXHAUST MUFFLER Bolts FOOT BOARD REMOVAL Remove front fender. (See page 2-5) Remover rear fender. (See page 2-6) Remove the four bolts attaching the right/left foot board. FRONT CARRIER REMOVAL Remove the four bolts attaching front carrier at the right/left side. Bolts EXHAUST MUFFLER REMOVAL...
Page 45: Taillight Bulb
. FRAME COVERS/EXHAUST MUFFLER Inspect the gasket. If the exhaust gas leaks, the gasket should be replaced. Install by reversing the removal sequence. Torque: Exhaust muffler lock bolt 35 N-m (3.5 kgf-m, 25 lbf-ft) Exhaust muffler lock nut (90cc/70cc/50cc- Gasket 20 N-m (2 kgf-m, 15 lbf-ft) Exhaust muffler lock nut (50cc-4T) 10 N-m (1 kgf-m, 7 lbf-ft)
Page 46: Inspection/Adjustment
. INSPECTION/ADJUSTMENT __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ INSPECTION/ADJUSTMENT __________________________________________________________________________________ SERVICE INFORMATION------------------------------------------------ 3- 1 MAINTENANCE SCHEDULE-------------------------------------------- 3- 3 FUEL LINE/THROTTLE OPERATION --------------------------------- 3- 4 AIR CLEANER -------------------------------------------------------------- 3- 5 SPARK PLUG/CYLINDER COMPRESSION -------------------------- 3- 7 VALVE CLEARANCE (90cc/70cc/50cc-4T) --------------------------- 3- 8 CARBURETOR IDLE SPEED -------------------------------------------- 3- 8 ENGINE OIL (90cc/70cc/50cc-4T) --------------------------------------- 3- 9 TRANSMISSION OIL ------------------------------------------------------ 3-11...
Page 47: Inspection/Adjustment
. INSPECTION/ADJUSTMENT SERVICE INFORMATION GENERAL ！ WARNING •Before running the engine, make sure that the working area is well-ventilated. Never run the engine in a closed area. The exhaust contains poisonous carbon monoxide gas which may cause death to people. •Gasoline is extremely flammable and is explosive under some conditions.
Page 48 . INSPECTION/ADJUSTMENT Ignition timing : 90 cc BTDC 13°/1800rpm : 70 cc BTDC 13°/1800rpm : 50 cc-4T BTDC 13°/2000rpm : 50 cc-2T BTDC 15°/1700rpm CHASSIS Front brake free play: 10～20 mm (0.4～0.8 in) Drive chain slack: 10～20 mm (0.4～0.8 in) TIRE PRESSURE 1 Rider Front...
Page 49: Maintenance Schedule
Check all chassis fittings and ○ ○ ○ ○ ○ Fitting/Fasteners fasteners. Correct if necessary. Clean ○ ○ ○ Spark arresterl • In the interest of safety, we recommend these items should be serviced only by an authorized KYMCO motorcycle dealer.
Page 50: Fuel Line/Throttle Operation
. INSPECTION/ADJUSTMENT Fuel Filter FUEL LINE Check the fuel tubes and replace any parts, which show signs of deterioration, damage or leakage. ＊ Do not smoke or allow flames or sparks in your working area. Fuel Tubes Rubber Sleeves THROTTLE OPERATION Check the throttle to swing for smooth movement.
Page 51: Air Cleaner
. INSPECTION/ADJUSTMENT ＊ Reference tip alignment within 1mm of index mark on open side is acceptable. However, the aligning mark on the control lever must never be on the closed side of the index mark, otherwise engine damage will occur because of insufficient lubrication.
Page 52 . INSPECTION/ADJUSTMENT Screws To replace the air cleaner (50cc-2T) 1. Remove the five screws and air filter case cover. Air Filter Case Cover 2. Remove the air filter element, and separate it from the box. To clean the air filter element: 1.
Page 53: Spark Plug/Cylinder Compression
. INSPECTION/ADJUSTMENT SPARK PLUG Remove the ignition coil cap and spark plug. Check the spark plug for wear and fouling deposits. Clean any fouling deposits with a spark plug cleaner or a wire brush. Specified Spark Plug: 90cc/70cc/50cc-4T: NGK: CR7HSA 50cc-2T: NGK: BR8HAS Ignition Coil Cap/Spark Plug...
Page 54: Valve Clearance (90Cc/70Cc/50Cc-4T)
. INSPECTION/ADJUSTMENT Cylinder Head Cover VALVE CLEARANCE (90cc/70cc/50cc-4T) ＊ Inspect and adjust valve clearance while the engine is cold (below 35°C). Disconnect the oil recycle tube at the cylinder head cover. Remove the four bolts and cylinder head cover. Remove the two screws and two bolts, then Bolts remove the fan cover.
Page 55: Engine Oil (90Cc/70Cc/50Cc-4T)
. INSPECTION/ADJUSTMENT Bolts ENGINE OIL (90cc/70cc/50cc-4T) OIL LEVEL Remove the two bolts and right side cover. Place the machine on a level place. Warm up the engine for several minutes and stop it. Remove the dipstick and wipe it off with a clean rag.
Page 56 . INSPECTION/ADJUSTMENT ENGINE OIL REPLACEMENT AND OIL FILTER CLEANING A. Place the machine on a level place. B. Warm up the engine for several minutes and stop it. C. Place a container under the engine. D. Remove the oil filler cap and oil filter cap to drain the oil.
Page 57: Transmission Oil
. INSPECTION/ADJUSTMENT Oil Filter Bolt/Measurement Hole TRANSMISSION OIL TRANSMISSION OIL MEASUREMENT Place the machine on a level place. Remove the oil filler bolt and check the oil level. It should be up to the brim of the hole. If the level is low, add oil to raise it to the proper level.
Page 58: Drive Belt/Brake Shoes/Brake Pads/Brake Fluid
. INSPECTION/ADJUSTMENT Drive Belt DRIVE BELT Remove the left crankcase cover. Inspect the drive belt for cracks, scaling, chipping or excessive wear. Measure the V-belt width Service limit: 90cc: 16.5 mm (0.66 in) 70cc: 16.5 mm (0.66 in) 50cc-4T: 17 mm (0.68 in) 50cc-2T: 17.5 mm (0.7 in) Replace the drive belt if out of specification.
Page 59: Brake Lever Free Play (Drum Brake)
. INSPECTION/ADJUSTMENT BRAKE LEVER FREE PLAY (DRUM BRAKE) The brake lever free play (A) should be adjusted to 10~20 mm (0.4~0.8 in) at the tip of the brake lever. FRONT BRAKE FREE PLAY ADJUSTMENT Loosen the upper lock nut and fully turn in the adjusting bolt.
Page 60: Steering System Inspection
. INSPECTION/ADJUSTMENT ＊ Make sure the cut-out on the adjusting nut Is seated on the brake arm pin after making final free play adjustment. Arm Pin Adjusting Nut STEERING SYSTEM INSPECTION Place the machine on a level place. Check the steering column bushings and bearings: Move the handlebar up and down, and/or back and forth.
Page 61: Toe-In Adjustment
. INSPECTION/ADJUSTMENT TOE-IN ADJUSTMENT Place the machine on a level place. Measure the toe-in Adjust if out of specification. Toe-in measurement steps: Mark both front tire tread centers. Raise the front end of the machine so that there is no weight on the front tires. Fix the handlebar straight ahead.
Page 62: Wheels/Tires
. INSPECTION/ADJUSTMENT WHEELS/TIRES Check the tires for cuts, imbedded nails or other damages. Check the tire pressure. ＊ Tire pressure should be checked when tires are cold. TIRE PRESSURE 1 Rider Front 25kPa(0.22kgf/cm²,3.6psi) Rear 25kPa(0.22kgf/cm²,3.6psi) Front Axle Nut 90 cc: Front: 18*7-8 Rear : 18*9-8 70cc/50cc:...
Page 63: Drive Chain Slack Adjustment
. INSPECTION/ADJUSTMENT Inspect the wheel. Replace if damage or bends Always balance the wheel when a tire or wheel has been changed or replaced. ＊ • Never attempt even small repairs to the wheel. • Ride conservatively after installing a tire to allow it to seat itself properly on the rim.
Page 64 . INSPECTION/ADJUSTMENT Turn the adjusting nut, to decrease or increase chain slack. Retighten the upper and lower axle holding bolts. Torque: 70 N-m (7 kgf-m, 50 lbf-fi) Adjusting Nut Drive chain cleaning and lubrication The drive chain is equipped with rubber O- rings between the chain plates.
Page 65: Cable Inspection And Lubrication
. INSPECTION/ADJUSTMENT CABLE INSPECTION AND LUBRICATION ＊ Damaged cable sheath may cause corrosion and interfere with the cable movement. An unsafe condition may result so replace such cable as soon as possible. Inspect the cable sheath. Replace if damage. Check the cable operation. Lubricate or replace if unsmooth operation.
Page 66: Headlight Beam Adjustment (On Road Only)
. INSPECTION/ADJUSTMENT Adjusting screw HEADLIGHT BEAM ADJUSTMENT (ON ROAD ONLY) Vertical adjustment: Turn the ignition switch ON and start the engine. Turn on the headlight switch. Adjust the headlight aim by turning the headlight aim adjusting screw. Headlight BRAKE PEDAL ADJUSTMENT ( ON ROAD ONLY) The brake pedal free play should be adjusted to 5~10 mm (0.2~0.4 in) at the...
Page 67: Brake Fulid
. INSPECTION/ADJUSTMENT Brake Pedal Cable 7. Loosen the locknut. (Brake pedal cable) 8. Turn the adjusting bolt until the specified free play is obtained. 9. Tighten the locknut. (Brake pedal cable) Adjusting Blot Locknut BRAKE FLUID Check if the fluid level is below the lower level mark through the inspection window.
Page 68: Lubrication System
. LUBRICATION SYSTEM __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ LUBRICATION SYSTEM __________________________________________________________________________________ SERVICE INFORMATION (90cc/70cc/50cc-4T) ---------------------- 4- 3 SERVICE INFORMATION (50cc-2T) ----------------------------------- 4- 4 ENGINE OIL/OIL FILTER (90cc/70cc/50cc-4T)----------------------- 4- 5 OIL PUMP (90cc) ----------------------------------------------------------- 4- 5 OIL PUMP (70cc/50cc-4T)------------------------------------------------- 4- 9 OIL PUMP BLEEDING (50cc-2T)---------------------------------------- 4-15 OIL TANK (50cc-2T) ------------------------------------------------------- 4-16 OIL PUMP (50cc-2T) ------------------------------------------------------- 4-17...
Page 69: Lubrication System
. LUBRICATION SYSTEM LUBRICATION SYSTEM (90cc/70cc/50cc-4T) Rocker Arm Shaft Crankshaft Oil Filter Screen Oil Pump...
Page 70 . LUBRICATION SYSTEM LUBRICATION SYSTEM (50cc-2T)
Page 71: Service Information (90Cc/70Cc/50Cc-4T)
. LUBRICATION SYSTEM SERVICE INFORMATION (90cc/70cc/50cc-4T) GENERAL INSTRUCTIONS • The maintenance of lubrication system can be performed with the engine installed in the frame. • Use care when removing and installing the oil pump not to allow dust and foreign matters to enter the engine and oil line.
Page 72: Service Information (50Cc-2T)
. LUBRICATION SYSTEM SERVICE INFORMATION (50cc-2T) GENERAL INSTRUCTIONS • Use care when removing and installing the oil pump not to allow dust and dirt to enter the engine and oil line. • Do not attempt to disassemble the oil pump. •...
Page 73: Engine Oil/Oil Filter (90Cc/70Cc/50Cc-4T)
. LUBRICATION SYSTEM ENGINE OIL/OIL FILTER (90cc/70cc/50cc-4T) OIL LEVEL AND OIL CHANGE Refer to the “ENGINE OIL” section in the chapter 3 to check the oil level and replacement and oil filter cleaning. Right Crankcase Cover OIL PUMP (90cc) REMOVAL Place a container under the engine.
Page 74 . LUBRICATION SYSTEM Oil Pump Remove the two oil pump mounting bolts and the oil pump. Bolts Oil Pump Body DISASSEMBLY Remove the screw and disassemble the oil pump. Screws Outer Rotor INSPECTION Measure the pump body-to-outer rotor clearance. Service Limit: 0.25 mm (0.01 in) Oil Pump Body...
Page 75 . LUBRICATION SYSTEM Outer Rotor Measure the inner rotor-to-outer rotor clearance. Service Limit: 0.2 mm (0.008 in) Inner Rotor Measure the rotor end-to-pump body clearance. Service Limit: 0.12 mm (0.0048 in) Outer Rotor Inner Rotor ASSEMBLY Install the outer rotor, inner rotor and pump shaft into the pump body.
Page 76 . LUBRICATION SYSTEM Screws Tighten the screw to secure the pump cover. Make sure that the pump shaft rotates freely without binding. Arrow Mark INSTALLATION Reverse the “OIL PUMP REMOVAL” procedures. Make sure that the pump shaft rotates freely without binding. ＊...
Page 77: Oil Pump (70Cc/50Cc-4T)
. LUBRICATION SYSTEM OIL PUMP (70cc/50cc-4T) Bolts REMOVAL Place a container under the engine. Remove the drain plug to drain the oil ( page Bolts 3-9 ). Remove the A.C. generator flywheel (page Bolts 14-8). Remove the A.C. generator stator and pulsar coil (page 14-8).
Page 78 . LUBRICATION SYSTEM Bolts Remove three oil pump mounting bolts and the oil pump. Oil Pump O-rings Dowel Pin Remove O-rings and dowel pin. 4-10...
Page 79 . LUBRICATION SYSTEM DISASSEMBLY Remove the screws and disassemble the oil pump. Bolts Screws Outer Rotor Pump Body INSPECTION Measure the pump body-to-outer rotor clearance. Service Limit: 0.25 mm (0.01 in) Outer Rotor Measure the inner rotor-to-outer rotor clearance. Service Limit: 0.2 mm (0.008 in) Inner Rotor 4-11...
Page 80 . LUBRICATION SYSTEM Measure the rotor end-to-pump body clearance. Service Limit: 0.12 mm (0.0048 in) Inner Rotor ASSEMBLY Dowel Pin Install the outer rotor, inner rotor and pump shaft into the pump body. ＊ Insert the pump shaft by aligning the flat on the shaft with the flat in the inner rotor.
Page 81 . LUBRICATION SYSTEM INSTALLATION O-rings Dowel Pin Install the O-rings and dowel pin. ＊ Inspect the O-rings and replace if damaged. Bolts Install the oil pump and tighten the bolts. Make sure that the pump shaft rotates freely without binding. Oil Pump Oil Pump Gear Install the oil pump gear and tighten the nut.
Page 82 . LUBRICATION SYSTEM Install the right crankcase cover and tighten Bolts the bolts. Right Crankcase Cover 4-14...
Page 83: Oil Pump Bleeding (50Cc-2T)
. LUBRICATION SYSTEM Oil Pump OIL PUMP BLEEDING (50cc-2T) ＊ • Air in the oil tubes will block oil flow and result in severe engine damage. • Bleed air from the oil tubes and oil pump whenever the oil tubes or pump have been removed or there is air in the oil tubes.
Page 84 . LUBRICATION SYSTEM OIL TANK (50cc-2T) OIL TANK REMOVAL Remove the oil level switch connector. Remove the two bolts attaching the oil tank. Bolts Oil Level Switch Connector Oil Inlet Tube Disconnect the oil inlet tube. Drain the oil inside the oil tank into a clean container.
Page 85 . LUBRICATION SYSTEM Oil Inlet Tube OIL PUMP (50cc-2T) REMOVAL ＊ Do not allow foreign matters to enter the crankcase. Before removing the oil pump, clean the oil pump and crankcase surfaces. Disconnect the oil outlet tube from the oil pump.
Page 86: Oil Filter Cleaning (50Cc-2T)
. LUBRICATION SYSTEM OIL PUMP INSTALLATION ＊ • Lubricate the O-ring with grease or engine oil before installation. • Make sure that the oil pump is inserted into the crankcase. • Apply molybdenum disulfide or grease to the pump pinion. Install the oil pump into the crankcase.
Page 87: Fuel System
. FUEL SYSTEM __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ FUEL SYSTEM __________________________________________________________________________________ SERVICE INFORMATION------------------------------------------------ 5- 2 FUEL TANK ----------------------------------------------------------------- 5- 4 FUEL VALVE REMOVAL ------------------------------------------------ 5- 4 THROTTLE VALVE---------------------------------------------------------- 5- 7 AIR CLEANER (90cc/70cc/50cc-4T) ------------------------------------ 5- 9 AIR CLEANER (50cc-2T) ------------------------------------------------- 5-10 CARBURETOR-------------------------------------------------------------- 5-11 REED VAVLE (50cc-2T) -------------------------------------------------- 5-16...
Page 88: Fuel System
. FUEL SYSTEM...
Page 89: Service Information
. FUEL SYSTEM SERVICE INFORMATION GENERAL INSTRUCTIONS Gasoline is very dangerous. When working with gasoline, keep sparks and flames away from the working area. Gasoline is extremely flammable and is explosive under certain conditions. Be sure to work in a well-ventilated area. •...
Page 90 . FUEL SYSTEM TROUBLESHOOTING Engine cranks but won’t start Engine lacks power • No fuel in tank • Clogged air cleaner • No fuel to carburetor • Faulty carburetor • Cylinder flooded with fuel • Faulty ignition system • No spark at plug •...
Page 91: Fuel Tank
. FUEL SYSTEM FUEL TANK REMOVAL Warning • Keep sparks and flames away from the work area. • Wipe off any spilled gasoline. Remove front fender (See page 2-5). Screws Switch the fuel valve “OFF”. Disconnect the fuel outlet tube from fuel valve.
Page 92 . FUEL SYSTEM Control Shaft Screws Washer DISASSEMBLY Remove the two screws on the retaining ring and then remove retaining ring. Remove the washer and control shaft. Retaining Ring Fuel Valve Body Rubber Gasket Remove the rubber gasket from the fuel valve body.
Page 93 . FUEL SYSTEM Main Fuel Tube INSTALLATION Reverse the “FUEL VALVE REMOVEAL” procedures. Connect all fuel tube. Outlet Fuel Tube Reserve Fuel Tube...
Page 94: Throttle Valve
. FUEL SYSTEM Carburetor Cap THROTTLE VALVE DISASSEMBLY Remove the fuel tank. (Refer to “FUEL TANK” section in the chapter 5) Remove the carburetor cap. Pull out the throttle valve. Throttle Valve Throttle Cable Compress the spring to disconnect the throttle cable by hand.
Page 95 . FUEL SYSTEM Throttle Valve Needle Retainer Pry off the needle retainer and remove the jet needle. Check the throttle valve and jet needle for wear or damage. ASSEMBLY Reverse the “DISASSEMBLY” procedures. Jet Needle Groove Install the throttle valve into the carburetor body.
Page 96: Air Cleaner (90Cc/70Cc/50Cc-4T)
. FUEL SYSTEM AIR CLEANER (90cc/70cc/50cc-4T) CLEANING Refer to “AIR CLEANER” section in the chapter 3. REMOVAL Remove front fender. (See page 2-5) Disconnect the oil recycle tube from cylinder head and frame. Bolt Oil Recycle Tube Remove the bolt at the air cleaner left side. Band Loosen the screw at the band and remove bolt at the air cleaner right side, then remove air cleaner.
Page 97: Air Cleaner (50Cc-2T)
. FUEL SYSTEM Air Inlet Hose AIR CLEANER (50cc-2T) CLEANING Refer to “AIR CLEANER” section in the chapter 3. REMOVAL Remove front fender. (See page 2-5) Disconnect the air inlet hose from the frame. Remove the bolt at the air cleaner left side. Bolt Loosen the screw at the band and remove bolt at the air cleaner right side, then remove air cleaner.
Page 98: Carburetor
. FUEL SYSTEM CARBURETOR REMOVAL Remove the fuel tank, carburetor cap and air filter. (Refer to chapter 5) Loosen the drain plug to drain the gasoline from the float chamber. ＊ • Keep sparks and flames away from the work area. •...
Page 99 . FUEL SYSTEM Auto Bystarte DISASSEMBLY Remove auto bystarter cap. Remove the two screws and then remove auto bystarter and plate. Auto Bystarter Cap Screws Screws Remove the three float chamber screws and remove the float chamber. Float Chamber Float Valve Float Pull out the float pin, then remove float and float valve.
Page 100 . FUEL SYSTEM Spring Washer O-ring CAUTIONS! ＊ • Be careful not to damage the jets and jet holder when removing them. • Before removal, turn the throttle stop screw and air screw in and count the number of turns until they seat lightly and then make a note of this.
Page 101 . FUEL SYSTEM CARBURETOR CLEANING Blow compressed air through all passages of the carburetor body. FLOAT/FLOAT VALVE INSPECTION Inspect the float valve seat for wear or damage. Inspect the float for damage or fuel level inside the float chamber. O-ring FUEL RESERVOIR O-RING CHECK Remove the O-ring.
Page 102 . FUEL SYSTEM AUTO BYSTARTER INSPECTION Measure the resistance between the auto bystarter wire terminals. Resistance: 5Ω (10 minutes minimum after stopping the engine) If the resistance exceeds 5Ω, replace the auto bystarter with a new one. After the engine stops for 30 minutes, connect a hose to the fuel enriching circuit and blow the hose with mouth.
Page 103 . FUEL SYSTEM Intake Manifold REED VALVE (50cc-2T) REMOVAL Remove the oil pimp control cable plate. (See page 4-17) Remove carburetor. (See page 5-11) Remove the three intake manifold bolts and gasket. Remove the reed valve and gasket. Bolts Reed Stopper Reed Stopper Reeds INSPECTION...
Page 104: Engine Removal
. ENGINE REMOVAL __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ ENGINE REMOVAL __________________________________________________________________________________ SERVICE INFORMATION------------------------------------------------ 6- 1 ENGINE REMOVAL (90cc/70cc/50cc-4T) ----------------------------- 6- 2 ENGINE REMOVAL (50cc-2T) ------------------------------------------ 6- 4...
Page 105 6. ENGINE REMOVAL/INSTALLATION SERVICE INFORMATION GENERAL INSTRUCTIONS • A floor jack or other adjustable support is required to support and maneuver the engine. Be careful not to damage the machine body, cables and wires during engine removal. • Use shop towels to protect the machine body during engine removal. •...
Page 106 . ENGINE REMOVAL Bolts ENGINE REMOVAL (90cc/70cc/50cc-4T) Drain engine oil and transmission oil. (Refer to chapter 3) Remove frame covers and exhaust pipe. (Refer chapter 2) Remove air cleaner and carburetor. (Refer to chapter 5) Remove the two bolts on the drive sprocket. Drive Sprocket Remove the drive sprocket and washer.
Page 107 6. ENGINE REMOVAL/INSTALLATION Remove the engine assembly to the left side of the machine. INSTALLATION Reverse the “REMOVAL” procedures. TORQUE VALUES Engine bracket bolt 27 N-m (2.7 kgf-m, 19 lbf-ft) Front engine mounting bolt 45 N-m (4.5 kgf-m, 32 lbf-ft) Rear engine mounting bolt 32 N-m (3.2 kgf-m, 23 lbf-ft)
Page 108 . ENGINE REMOVAL A.C. Generator/Starter Bolts Motor Couplers ENGINE REMOVAL (50cc-2T) Remove frame covers and exhaust pipe. (Refer to chapter 2) Remove oil tank. (Refer to chapter 4) Remove air cleaner and carburetor. (Refer to chapter 5) Drain transmission oil. (Refer to chapter 3) Disconnect the A.C.
Page 109 6. ENGINE REMOVAL/INSTALLATION Remove the engine assembly to the left side of the machine. INSTALLATION Reverse the “REMOVAL” procedures. TORQUE VALUES Engine bracket bolt 27 N-m (2.7 kgf-m, 19 lbf-ft) Front engine mounting bolt 45 N-m (4.5 kgf-m, 32 lbf-ft) Rear engine mounting bolt 32 N-m (3.2 kgf-m, 23 lbf-ft)
Page 110: Cylinder Head/Valves
. CYLINDER HEAD/VALVES (90cc/70cc/50cc-4T) __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ CYLINDER HEAD/VALVES (90cc/70cc/50cc-4T) __________________________________________________________________________________ SERVICE INFORMATION------------------------------------------------ 7- 2 CYLINDER HEAD COVER----------------------------------------------- 7- 5 CAMSHAFT/CAMSHAFT HOLDER------------------------------------ 7- 5 CYLINDER HEAD---------------------------------------------------------- 7-10...
Page 111: Cylinder Head/Valves
7. CYLINDER HEAD/VALVES (90cc/70cc/50cc-4T)
Page 112: (90Cc/70Cc/50Cc-4T)
. CYLINDER HEAD/VALVES (90cc/70cc/50cc-4T) SERVICE INFORMATION GENERAL INSTRUCTIONS • The cylinder head can be serviced with the engine installed in the frame. • When assembling, apply molybdenum disulfide grease or engine oil to the valve guide movable parts, valve arm and camshaft sliding surfaces for initial lubrication. •...
Page 113 7. CYLINDER HEAD/VALVES (90cc/70cc/50cc-4T) 50cc-4T mm (in) Item Standard Service Limit ⎯ 0.04 (0.0016) Valve clearance (cold) ⎯ 0.04 (0.0016) ⎯ Cylinder head compression pressure 14 kg/cm²(1400 kpa, 198.8 psi) ⎯ Cylinder head warpage 0.05 (0.002) 25.761 (1.03044) 25.65 (1.026) Camshaft cam height 25.563 (1.02252) 25.45 (1.018)
Page 114 . CYLINDER HEAD/VALVES (90cc/70cc/50cc-4T) TROUBLESHOOTING • The poor cylinder head operation can be diagnosed by a compression test or by tracing engine top-end noises. Poor performance at idle speed White smoke from exhaust muffler • Compression too low • Worn valve stem or valve guide •...
Page 115: Cylinder Head Cover
7. CYLINDER HEAD/VALVES (90cc/70cc/50cc-4T) Bolts CYLINDER HEAD COVER REMOVAL Remove fuel tank. (Refer to the chapter 5) Disconnect the oil recycle tube at the cylinder head cover. Remove the four bolts at the cylinder head cover, then remove the cylinder head cover. Cylinder Head Cover INSTALLATION Install a new cylinder head cover O-ring...
Page 116: Cylinder Head
. CYLINDER HEAD/VALVES (90cc/70cc/50cc-4T) Nuts and Washers Remove the four camshaft holder nuts and washers. ＊ Diagonally loosen the cylinder head nuts in 2 or 3 times. Camshaft Holder Remove the camshaft holder and dowel pins. Camshaft Remove the camshaft gear from the cam chain and remove the camshaft.
Page 117 7. CYLINDER HEAD/VALVES (90cc/70cc/50cc-4T) Camshaft Holder Rocker Arm CAMSHAFT HOLDER INSPECTION Inspect the camshaft holder for wear or damage. Inspect the rocker arm shaft for blue discoloration or grooves. If any defects are found, replace the rocker arm shaft with a new one, then inspect lubrication system.
Page 118 . CYLINDER HEAD/VALVES (90cc/70cc/50cc-4T) CAMSHAFT HOLDER ASSEMBLY Reverse the “CAMSHAFT HOLDER DISASSEMBLY” procedures. ＊ Align the cross cutout on the exhaust valve rocker arm shaft with the bolt of the camshaft holder. Camshaft Bearings CAMSHAFT INSPECTION Check each camshaft bearing for play or damage.
Page 119 7. CYLINDER HEAD/VALVES (90cc/70cc/50cc-4T) Dowel Pins INSTALLATION Reverse the “CAMSHAFT REMOVAL” procedures. Note the following points: 1. Turn the flywheel so that the “T” mark on the flywheel aligns with the index mark on the crankcase. Keep the round hole on the camshaft gear facing up and align the punch marks on the camshaft gear with the cylinder head surface (Position the intake and...
Page 120 . CYLINDER HEAD/VALVES (90cc/70cc/50cc-4T) Nuts CYLINDER HEAD REMOVE Remove the camshaft. (Refer to the “camshaft remove” section in the chapter 7) Remove the carburetor. (Refer to the “CARBURETOR REMOVE” section in the chapter 5) Remove the exhaust muffler. (Refer to the “EXHAUST MUFFLER REMOVE”...
Page 121 7. CYLINDER HEAD/VALVES (90cc/70cc/50cc-4T) Valve Cotter Retainer Springs Springs Seat CYLINDER HEAD DISASSEMBLY Remove the valve spring cotters, retainers, springs, spring seats, oil seals and valves using a valve spring compressor. ＊ • Be sure to compress the valve springs with a valve spring compressor.
Page 122 . CYLINDER HEAD/VALVES (90cc/70cc/50cc-4T) VALVE SPRING INSPECTION Measure the free length of the inner and outer valve springs. Service Limit: 90cc: Inner: 30.8 mm (1.232 in) Outer: 33.5 mm (1.34 in) 70cc: Inner: 28.4 mm (1.136 in) Outer: 32 mm (1.28 in) 50cc-4T: 34 mm (1.36 in) Measure compressed force (valve spring)
Page 123 7. CYLINDER HEAD/VALVES (90cc/70cc/50cc-4T) ASSEMBLY Install the valve spring seats and oil seal. ＊ Be sure to install new oil seal. Lubricate each valve with engine oil and insert the valves into the valve guides. Install the valve springs and retainers. Compress the valve springs using the valve spring compressor, then install the valve cotters.
Page 124: Cylinder/Piston
. CYLINDER/PISTON __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ CYLINDER /PISTON __________________________________________________________________________________ SERVICE INFORMATION (90cc/70cc/50cc-4T) ---------------------- 8- 3 SERVICE INFORMATION (50cc-2T) ----------------------------------- 8- 5 CYLINDER/PISTON (90cc/70cc/50cc-4T)------------------------------ 8- 6 CYLINDER HEAD (50cc-2T) --------------------------------------------- 8-11 CYLINDER/PISTON (50cc-2T)------------------------------------------- 8-14...
Page 125 . CYLINDER/PISTON 90cc/70cc/50cc-4T...
Page 126 . CYLINDER/PISTON 50cc-2T...
Page 127 . CYLINDER/PISTON SERVICE INFORMATION (90cc/70cc/50cc-4T) GENERAL INSTRUCTIONS • The cylinder and piston can be serviced with the engine installed in the frame. • Before disassembly, clean the engine to prevent dust from entering the engine. • Remove all gasket material from the mating surfaces. •...
Page 128 . CYLINDER/PISTON TROUBLESHOOTING • When hard starting or poor performance at low speed occurs, check the crankcase breather for white smoke. If white smoke is found, it means that the piston rings are worn, stuck or broken. Compression too low or uneven compression Excessive smoke from exhaust muffler •...
Page 129 . CYLINDER/PISTON SERVICE INFORMATION (50cc-2T) GENERAL INSTRUCTIONS • The cylinder head, cylinder and piston can be serviced with the engine installed in the frame. • Before disassembly, clean the engine to prevent dust from entering the engine. • Remove all gasket material from the mating surfaces. •...
Page 130 . CYLINDER/PISTON Dowel Pins CYLINDER/PISTON (90cc/70cc/50cc-4T) REMOVAL Remove the cylinder head. (Refer to the chapter 7) Remove the two dowel pins and cylinder head gasket. Gasket Cylinder Remove cam chain guide and then remove cylinder. Cam Chain Guide Dowel Pins Remove the cylinder gasket and dowel pins.
Page 131 . CYLINDER/PISTON INSPECTION Inspect the piston, piston pin and piston rings. Remove the piston rings. ＊ Take care not to damage or break the piston rings during removal. Clean carbon deposits from the piston ring grooves. Inspect the piston wall for wear/scratches/damage.
Page 132 . CYLINDER/PISTON Measure the piston pin O.D. Service Limit: 12.96 mm (0.5184 in) Measure the piston O.D. ＊ Take measurement at 10mm from the 4 mm bottom and 90° to the piston pin hole. Service Limit: 90cc/70cc: 46.9 mm (1.876 in) 38.9 mm (1.556 in) 50cc-4T: Measure the piston-to-piston pin clearance.
Page 133 . CYLINDER/PISTON PISTON RING INSTALLATION Install the piston rings onto the piston. Apply engine oil to each piston ring. ＊ • Be careful not to damage or break the piston and piston rings. • All rings should be installed with the markings facing up.
Page 134 . CYLINDER/PISTON “IN” Mark PISTON INSTALLATION Remove any gasket material from the crankcase surface. ＊ Be careful not to drop foreign matters into the crankcase. Install the piston, piston pin and a new piston pin clip. ＊ • Position the piston “IN” mark on the intake valve side.
Page 135 . CYLINDER/PISTON Spark Plug Cap CYLINDER HEAD (50cc-2T) REMOVAL Remove the spark plug cap. Remove the exhaust muffler. ( 2-7) Fan Cover/Engine Hood Remove the three bolts attaching the fan cover to remove the fan cover. Remove the bolt attaching the engine hood to remove the engine hood.
Page 136 . CYLINDER/PISTON Combustion Chamber COMBUSTION CHAMBER DECABONIZING Remove the carbon deposits from the combustion chamber ＊ Avoid damaging the combustion cham- ber wall and cylinder mating surface. Mating Surface CYLINDER HEAD INSPECTION Check the cylinder head for warpage with a straight edge and feeler gauge.
Page 137 . CYLINDER/PISTON Cylinder head Bolts Cylinder Head Bolts Installation Install and tighten the cylinder head bolts diagonally in 2 or 3 times. Torque: 10 N-m (1 kgf-m, 7 lbf-ft) Install the spark plug. Torque: 15 N-m (1.5 kgf-m, 11 lbf-ft) Cylinder Head Spark Plug Engine Hood...
Page 138 . CYLINDER/PISTON Cylinder CYLINDER/PISTON (50cc-2T) CYLINDER REMOVAL Remove the cylinder head. Remove the exhaust muffler. (See page 2-7) Remove the reed valve. (See page 5-16) Remove the cylinder. Remove the cylinder gasket. ＊ Do not pry between the cylinder and crankcase or strike the fins.
Page 139 . CYLINDER/PISTON CYLINDER/PISTON INSPECTION Check the cylinder and piston for wear or damage. Clean carbon deposits from the exhaust port area. ＊ Be careful not to damage the cylinder inside wall. Measure the cylinder bore at three levels of A, B and C in both X and Y directions. Avoid the port area.
Page 140 . CYLINDER/PISTON A Mark ＊ The cylinder has an “A” mark or no mark on it. When replacing the cylinder with a new one, use a cylinder having the same mark as the old one. Measure the piston O.D. at a point 3mm from the bottom of the piston skirt.
Page 141 . CYLINDER/PISTON PISTON RING INSPECTION Measure each piston ring end gap. Service Limits: Top/Second 0.4 mm (0.016 in) ＊ Set each piston ring squarely into the cylinder using the piston and measure the end gap. CONNECTING ROD SMALL END INSPECTION Install the piston pin and bearing in the connecting rod small end and check for excessive play.
Page 142 . CYLINDER/PISTON Cylinder Gasket “IN” Mark Install a new cylinder gasket on the mating surface between the cylinder and crankcase. Position the piston “IN” mark on the intake valve side. Make sure that the ring end gaps are aligned Ring Pins with the piston ring pins in the ring grooves.
Page 143: Drive And Driven Pulleys
DRIVE AND DRIVEN PULLEYS DRIVE AND DRIVEN PULLEYS SERVICE INFORMATION..............9-2 LEFT CRANKCASE COVER/KICK STARTER ........9-4 DRIVE PULLEY ..................9-7 CLUTCH/DRIVEN PULLEY ..............9-9...
Page 144 DRIVE AND DRIVEN PULLEYS...
Page 145: Service Information
DRIVE AND DRIVEN PULLEYS SERVICE INFORMATION GENERAL INSTRUCTIONS • The drive pulley, clutch and driven pulley can be serviced with the engine installed in the frame. • Avoid getting grease and oil on the drive belt and pulley faces. Remove any oil or grease from them to minimize the slipping of drive belt and drive pulley.
Page 146: Drive And Driven Pulleys
DRIVE AND DRIVEN PULLEYS TORQUE VALUES Drive face nut 60 N-m (6 kgf-m, 43 lbf-ft) Apply oil the threads Clutch outer nut 40 N-m (4 kgf-m, 29 lbf-ft) Drive plat nut 55 N-m (5.5 kgf-m, 40 lbf-ft) SPECIAL TOOLS Universal holder A120E00017 Clutch spring compressor A120E00034...
Page 147: Left Crankcase Cover/Kick Starter
DRIVE AND DRIVEN PULLEYS Left Crankcase Cover LEFT CRANKCASE COVER/KICK STARTER REMOVAL Remove left foot board. (See page 2-7) Remove the eight left crankcase cover bolts and left crankcase cover. Remove the gasket and dowel pins. ＊ Use specified genuine parts for Bolts replacement.
Page 148 DRIVE AND DRIVEN PULLEYS Return Spring Spindle INSPECTION Inspect the kick starter spindle and gear for wear or damage. Inspect the return spring for weakness or damage. Inspect the kick starter spindle bushings for wear or damage. Plastic Bushing Spindle Bushing Inspect the starter driven gear for wear or Friction Spring damage.
Page 149 DRIVE AND DRIVEN PULLEYS Friction Spring Kick Starter Spindle Cover Install the starter driven gear and friction spring onto the left crankcase cover as the figure shown. Install the kick starter spindle cover and tighten three bolts. ＊ Apply grease on to the driven gear shaft. Starter Driven Gear Bolts Circlip...
Page 150: Drive Pulley
DRIVE AND DRIVEN PULLEYS Starting Ratchet DRIVE PULLEY REMOVAL Remove the left crankcase cover. (Refer to the “LEFT CRANKCASE COVER REMOVAL” section in the chapter 9) Hold the drive pulley using a universal holder and remove the drive face nut and washer.
Page 151 DRIVE AND DRIVEN PULLEYS INSPECTION Check each weight roller for wear or damage. Measure each weight roller O.D. Service Limit: 15.4 mm (0.616 in) Measure the movable drive face bushing I.D. Service Limit: 90cc: 24.06 mm (0.9624 in) 70cc/50cc: 20.6 mm (0.824 in) ASSEMBLY Install the weight rollers into the movable drive face.
Page 152: Clutch/Driven Pulley
DRIVE AND DRIVEN PULLEYS Clutch Outer Universal Holder CLUTCH/DRIVEN PULLEY REMOVAL Remove the left crankcase cover. (Refer to the “LEFT CRANKCASE COVER REMOVAL” section in the chapter 9) Remove the drive pulley. (Refer to the “DRIVE PULLEY REMOVAL” section in the chapter 9) Hold the clutch outer with the universal holder, then remove the clutch outer nut and...
Page 153 DRIVE AND DRIVEN PULLEYS CLUTCH/DRIVEN PULLEY Lock Nut Wrench, 39mm DISASSEMBLY Hold the clutch/driven pulley assembly with the clutch spring compressor. ＊ Be sure to use a clutch spring compressor to avoid spring damage. Clutch Spring Compressor A120E00034 Clutch Spring Compressor Set the clutch spring compressor in a vise and remove the clutch drive plate nut.
Page 154 DRIVE AND DRIVEN PULLEYS Measure the clutch lining thickness. Service Limit: 90cc/70cc: 2 mm (0.08 in) 50cc: 1 mm (0.04 in) INSPECTION Measure the driven face spring free length. Service Limit: 90cc: 137.5 mm (5.5 in) 70cc: 92 mm (3.68 in) 50cc-4T: 90 mm (3.6 in) 50cc-2T:...
Page 155 DRIVE AND DRIVEN PULLEYS Check the movable driven face for wear or damage. Measure the movable driven face I.D. Service Limit: 34.06 mm (1.3624 in) Inner Needle Bearing DRIVEN PULLEY FACE BEARING REPLACEMENT Drive the inner needle bearing out of the driven pulley face.
Page 156 DRIVE AND DRIVEN PULLEYS CLUTCH DISASSEMBLY Circlip Remove the circlips to disassemble the clutch. ＊ Keep grease off the clutch linings. Clutch Lining CLUTCH / DRIVEN PULLEY ASSEMBLY 9-13...
Page 157 DRIVE AND DRIVEN PULLEYS Install the damper rubbers on the drive plate pins. Install the clutch weights/shoes and clutch springs. Set the circlips in the groove. Clean the driven pulley faces and remove any grease from them. Install the oil seal onto the moveable driven face.
Page 158 DRIVE AND DRIVEN PULLEYS INSTALLATION Install the clutch/driven pulley and driven belt onto the drive shaft. ＊ Keep grease off the drive shaft. Install the clutch outer. Hold the clutch outer with the universal holder. Install and tighten the clutch outer nut. Torque: 40 N-m (4 kgf-m, 29 lbf-ft) Universal Holder A120E00017...
Page 159: Final Reduction/Transmission System
.FINAL REDUCTION/ TRANSMISSION SYSTEM __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ FINAL REDUCTION/TRANSMISSION SYSTEM __________________________________________________________________________________ SERVICE INFORMATION------------------------------------------------ 10- 2 TRANSMISSION CASE COVER--------------------------------------------- 10- 3 10-0...
Page 160 .FINAL REDUCTION/ TRANSMISSION SYSTEM 10-1...
Page 161 .FINAL REDUCTION/ TRANSMISSION SYSTEM SERVICE INFORMATION GENERAL INSTRUCTIONS • The transmission system can be serviced with the engine installed in the frame. • When replacing the drive shaft, use a special tool to hold the bearing inner race for this operation. SPECIFICATIONS Specified Oil: GEAR OIL SAE 90# Oil Capacity:...
Page 162 .FINAL REDUCTION/ TRANSMISSION SYSTEM Bolts TRANSMISSION CASE COVER REMOVAL Remove the drive sprocket. ( 6 -2) Remove the left crankcase cover. ( 9-4) Remove the clutch/driven pulley. ( 9-9) Drain the transmission gear oil into a clean container. Remove the transmission case cover attaching bolts.
Page 163 .FINAL REDUCTION/ TRANSMISSION SYSTEM Primary Drive Axle PRIMARY DRIVE AXLE REMOVAL Remove the clutch/friven pulley. (Refer to chapter 9) Remove the primary drive axle. Inspect the final gear teeth. Blue discoloration/pitting/wear → Replace. Inspect the countershaft gear teeth. Blue discoloration/pitting/wear → Replace. 10-4...
Page 164 .FINAL REDUCTION/ TRANSMISSION SYSTEM Primary Drive Axle INSTALLATION Reverse the “TRANSMISSION REVOVAL” section procedures. Install the primary drive axle into the left crankcase. Final Shaft Install the final gear and final shaft into left crankcase. Countershaft Resin Washer Install the countershaft and washer into the left crankcase.
Page 165 Fill the engine with oil and install the oil filler bolt. (Refer to the “TRANSMISSION OIL REPLACEMENT” section in the chapter Specified Gear Oil: KYMCO SIGMA GEAR OIL 90# Oil Capacity: At change: 0.11 liter (0.1 lmp qt, 0.12 US qt) At disassembly: 0.12 liter (0.11 lmp qt, 0.13 US qt)
Page 166: Crankcase/Crankshaft
.CRANKSCASE/CRANKSHAFT __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ CRANKCASE/CRANKSHAFT __________________________________________________________________________________ SERVICE INFORMATION------------------------------------------------ 11- 3 CRANKCASE/CRANKSHAFT (90cc/70cc/50cc-4T) ----------------- 11- 4 CRANKCASE/CRANKSHAFT (50cc-2T) ------------------------------ 11- 7 11-0...
Page 167 .CRANKCASE/CRANKSHAFT 90cc/70cc/50cc-4T 11-1...
Page 168 .CRANKSCASE/CRANKSHAFT 50cc-2T 11-2...
Page 169 .CRANKCASE/CRANKSHAFT SERVICE INFORMATION GENERAL INSTRUCTIONS • This section covers crankcase separation to service the crankshaft. The engine must be removed for this operation. • The following parts must be removed before separating the crankcase. −Cylinder head ( Chapter 7 (90cc/70cc/50cc-4T)) −Cylinder/piston ( Chapter 8) −Drive and driven pulleys ( Chapter 9) −A.C.
Page 170 .CRANKSCASE/CRANKSHAFT Bolt CRANKCASE/CRANKSHAFT (90cc/70cc/50cc-4T) REMOVAL Remove the crankcase attaching bolt. Separate the left and right crankcase halves. ＊ • Do not damage the crankcase gasket surface. • Never use a driver to pry the crankcase mating surfaces apart. Crankshaft Remove the crankshaft from the left crankcase.
Page 171 .CRANKCASE/CRANKSHAFT CRANKSHAFT INSPECTION Measure the connecting rod small end I.D. Service Limit: 13.06 mm (0.5224 in) Measure the connecting rod small end free play (A). Service Limit: 0.6 mm (0.024 in) Measure the crankshaft run out (B). Service Limit: 0.1 mm (0.004 in) Measure the connecting rod big end side clearance (C).
Page 172 .CRANKSCASE/CRANKSHAFT CRANKCASE/CRANKSHAFT INSTALLATION Install the cam chain into the left crankcase. Install the dowel pins and a new gasket onto the left crankcase. ＊ Place the right crankcase over the crankshaft and onto the left crankcase. Install the crankshaft into the left crankcase. ＊...
Page 173 .CRANKCASE/CRANKSHAFT CRANKCASE/CRANKSHAFT (50cc-2T) REMOVAL Remove the crankcase attaching bolts. Bolt Crankcase Puller Attach the crankcase puller on the right crankcase and remove the right crankcase from the left crankcase. Special tool Crankcase puller A120E00026 CRANKSHAFT REMOVAL Crankcase Puller Attach the crankcase puller on the left crankcase and remove the crankshaft from the left crankcase.
Page 174 .CRANKSCASE/CRANKSHAFT Remove the remaining bearing on the crankshaft side using the universal bearing puller. Special tool Universal bearing puller A120E00030 Universal Bearing Puller CRANKSHAFT INSPECTION Measure the connecting rod big end side clearance. Service Limit: 0.6 mm (0.024 in) Measure the connecting rod big end radial clearance at two points in the X and Y directions.
Page 175 .CRANKCASE/CRANKSHAFT Measure the crankshaft runout. Service Limit 0.1mm (0.004 in) 0.15 mm (0.006 in) replace if over replace if over Check the crankshaft bearings for excessive play. The bearings must be replaced if they are noisy or have excessive play. Play Play Radial...
Page 176 A120E00014 Oil Seal And Bearing Install Install the crankshaft into the left crankcase. ＊ • Apply KYMCO ULTRA motor oil or molybdenum disulfide to the crank- shaft bearings and connecting rod big end. • Apply grease to the lip of the oil seal and then install it.
Page 177 .CRANKCASE/CRANKSHAFT Dowel Pins CRANKCASE ASSEMBLY Install the dowel pins and a new gasket to the crankcase mating surface. Assemble the crankcase halves. Special tool Crankshaft & crankcase install tool A120E00024 The distance between the right crankcase oil seal and crankcase surface is about 12.5±0.5 mm (0.5±0.0.02 in).
Page 178 .CRANKSCASE/CRANKSHAFT The distance between the left crankcase oil seal and crankcase surface is about 1 mm Oil Seal (0.04 in). 1.0mm Install and tighten the crankcase attaching bolts. ＊ After assembly, check the crankshaft for smooth operation. 11-12...
Page 179: Front Wheel/Front Brake/ Front Suspension/Steering
. FRONT WHEEL/FRONT BRAKE/FRONT SUSPENSION/STEERING SYSTEM __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ FRONT WHEEL/FRONT BRAKE/ FRONT SUSPENSION\STEERING SYSTEM __________________________________________________________________________________ SERVICE INFORMATION------------------------------------------------ 12- 2 FRONT WHEEL------------------------------------------------------------- 12- 4 FRONT BRAKE ------------------------------------------------------------- 12- 8 FRONT SUSPENSION ----------------------------------------------------- 12-10 STEERING SYSTEM------------------------------------------------------- 12-13 TIE-ROD---------------------------------------------------------------------- 12-17 12-0...
Page 180: Front Wheel/Front Brake/Front Suspension/Steering System
. FRONT WHEEL/FRONT BRAKE/FRONT SUSPENSION/STEERING SYSTEM 12-1...
Page 181: Service Information
. FRONT WHEEL/FRONT BRAKE/FRONT SUSPENSION/STEERING SYSTEM SERVICE INFORMATION GENERAL INSTRUCTIONS • Remove the machine frame covers before removing the front wheel. Jack the machine front wheel off the ground and be careful to prevent the machine from falling down. • During servicing, keep oil or grease off the brake drum and brake linings. •...
Page 182 . FRONT WHEEL/FRONT BRAKE/FRONT SUSPENSION/STEERING SYSTEM SPECIAL TOOLS Oil seal and bearing install A120E00014 TROUBLESHOOTING Hard steering (heavy) Front wheel wobbling •Insufficient tire pressure • Bent rim • Excessive wheel bearing play • Bent spoke plate • Faulty tire • Improperly tightened axle nut Steers to one side or does not track straight •...
Page 183: Front Wheel
. FRONT WHEEL/FRONT BRAKE/FRONT SUSPENSION/STEERING SYSTEM FRONT WHEEL REMOVAL Place the machine on a level place. Remove four nuts attaching the wheel panel and front wheel. Elevate the front wheels by placing a suitable stand under the frame. ＊ Support the machine securely so there is no danger of it falling over.
Page 184 . FRONT WHEEL/FRONT BRAKE/FRONT SUSPENSION/STEERING SYSTEM INSPECTION Measure the wheel run out. Replace wheel or check bearing play if out of specification Rim run out limits: Vertical: 2 mm (0.08 in) Lateral: 2 mm (0.08 in) Inspect the front wheel hub. Replace it if cracks or damage.
Page 185 . FRONT WHEEL/FRONT BRAKE/FRONT SUSPENSION/STEERING SYSTEM Side Collar FRONT WHEEL HUB DISASSEMBLY Remove the side collar. Remove the dust seal of each side. Dust Seal Remove the front wheel hub bearings and distance collar. Dust Seal Distance Collar Wheel Bearings Dust Seal 12-6...
Page 186 . FRONT WHEEL/FRONT BRAKE/FRONT SUSPENSION/STEERING SYSTEM ASSEMBLY Apply grease to a new dust seal lip and install the dust seal. Pack all bearing cavities with grease. Drive in the left bearing. Install the distance collar. Drive in the right bearing. ＊...
Page 187: Front Brake
. FRONT WHEEL/FRONT BRAKE/FRONT SUSPENSION/STEERING SYSTEM Brake Cable FRONT BRAKE REMOVAL Remove the wheel hub. (See page 12-4) Pull brake shoe plate out from steering knuckle. Disconnect the front brake cable from brake cam lever and remove the brake shoe plate. Brake Shoe Plate Brake Cam Lever INSPECTION...
Page 188 . FRONT WHEEL/FRONT BRAKE/FRONT SUSPENSION/STEERING SYSTEM Install the brake shoe plate. ＊ Make sure that the boss on the knuckle correctly engages with the locating slot on the brake shoe plate. Install front wheel. (See page 12-7) Adjust the front brake cable free play. Refer to the “BRAKE LEVER FREE Boss Locating Slot...
Page 189: Front Suspension
. FRONT WHEEL/FRONT BRAKE/FRONT SUSPENSION/STEERING SYSTEM Upper Bolt Shock Absorber FRONT SUSPENSION REMOVAL Elevate the front wheels by placing a suitable stand under the frame. ＊ Support the machine securely so there is no danger of it falling over. Remove the front wheel, wheel hub, brake shoe plate.
Page 190 . FRONT WHEEL/FRONT BRAKE/FRONT SUSPENSION/STEERING SYSTEM Check the front arm brackets of the frame. If bent, cracked or damaged, repair or replace the frame. Check the tightening torque of the front arms securing nuts. Torque: 45 N-m (4.5 kgf-m, 32 lbf-ft) Check the dust seal.
Page 191 . FRONT WHEEL/FRONT BRAKE/FRONT SUSPENSION/STEERING SYSTEM Bushes Inspect the front arm. Replace if cracks, bends or damage. ＊ Do not attempt to straighten a bent arm, this may dangerously weaken the arm. Inspect bushes. Replace if wear or damage. Bushes INSTALLATION Reverse the “REMOVAL”...
Page 192: Steering System
. FRONT WHEEL/FRONT BRAKE/FRONT SUSPENSION/STEERING SYSTEM STEERING SYSTEM HANDLEBAR REMOVAL Remove the following parts: Handlebar and Front fender. Refer to the “FRAME COVER” section in the CHAPTER 2 INSPECTION Inspect the handlebar. Replace if cracks, bends or damage. INSTALLATION Install handlebar and handlebar holder, then tighten the four bolts.
Page 193 . FRONT WHEEL/FRONT BRAKE/FRONT SUSPENSION/STEERING SYSTEM Cotter Pin STEERING COLUMN REMOVAL Remove handlebar. (Refer to “FRAME COVER” section in chapter 2) Remove the cotter pins and nuts attaching the tie-rods, then remove tie-rods. Remove the cotter pin and nut attaching the steering column, then remove steering column and collar.
Page 194 . FRONT WHEEL/FRONT BRAKE/FRONT SUSPENSION/STEERING SYSTEM Dust Seals Remove the dust seal of each frame side. Snap Ring Remove the snap ring. Remove the bearing. INSTALLATION Apply grease to a new dust seal lip and install the dust seal (under frame). Pack bearing cavities with grease.
Page 195 . FRONT WHEEL/FRONT BRAKE/FRONT SUSPENSION/STEERING SYSTEM Apply the grease onto the rubber collar and then install the rubber collar. Install the steering bracket and tighten the two bolts. Torque: 22 N-m (2.2 kgf-m, 16 lbf-ft) Install the tie rods and tighten the nuts. Torque: 35 N-m (3.5 kgf-m, 25 lbf-ft) Install the cotter pin and band ends of cotter pin.
Page 196: Tie-Rod
. FRONT WHEEL/FRONT BRAKE/FRONT SUSPENSION/STEERING SYSTEM TIE-ROD REMOVAL Remove the cotter pin and nut at the steering knuckle. Remove the cotter pin and nut at the steering column. Remove the tie-road. Cotter Pin Cotter Pin INSPECTION Inspect the tie-rod. Replace if bend or damage. Check the tie-rod end movement.
Page 197 . FRONT WHEEL/FRONT BRAKE/FRONT SUSPENSION/STEERING SYSTEM Set the rod-end (steering column side) in an To Knuckle Arm angle where the indentation surface of the tie-rod is parallel to the rod-end shaft, and then tighten the lock nut. Torque: 35 N-m (3.5 kgf-m, 25 lbf-ft) (Left Side) Set the other rod-end (knuckle arm side) in an angle as shown (right-hand tie-rod and...
Page 198: Rear Wheel /Swing Arm/Hydraulic Brake
. REAR WHEEL/SWING ARM/ HYDRAULIC BRAKE __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ REAR WHEEL/SWING ARM/ HYDRAULIC BRAKE __________________________________________________________________________________ SERVICE INFORMATION------------------------------------------------ 13- 2 REAR WHEEL--------------------------------------------------------------- 13- 4 REAR SWING ARM-------------------------------------------------------- 13-10 HYDRAULIC BRAKE ----------------------------------------------------- 13-15 BRAKE PAD/DISK --------------------------------------------------------- 13-16 BRAKE MASTER CYLINDER -------------------------------------------- 13-17 BRAKE CALIPER ---------------------------------------------------------- 13-20 DRUM BRAKE -------------------------------------------------------------- 13-22 13-0...
Page 199 . REAR WHEEL/SWING ARM/ HYDRAULIC BRAKE 13-1...
Page 200: Service Information
. REAR WHEEL/SWING ARM/ HYDRAULIC BRAKE SERVICE INFORMATION GENERAL INSTRUCTIONS • During servicing, keep oil or grease off the brake drum and brake linings. • During servicing, keep oil or grease off the brake disk and brake pads. • Drain the brake fluid from the hydraulic brake system before disassembly. •...
Page 201: Hydraulic Brake
. REAR WHEEL/SWING ARM/ HYDRAULIC BRAKE TROUBLESHOOTING Rear wheel wobbling Poor brake performance (Drum Brake) • Bent rim • Brake not adjusted properly • Faulty tire • Worn brake linings • Axle not tightened properly • Worn brake shoes at cam contacting area •...
Page 202 . REAR WHEEL/SWING ARM/ HYDRAULIC BRAKE REAR WHEEL REAR WHEEL REMOVAL Place the machine on a level place. Remove four nuts attaching the wheel. ＊ Elevate the rear wheels by placing a suitable stand under the rear of frame. Support the machine securely so there is no danger of it falling over.
Page 203 . REAR WHEEL/SWING ARM/ HYDRAULIC BRAKE Washer REAR WHEEL HUB REMOVAL Remove rear wheel nuts. (See page 13-4) Remove the wheel hub nut cover and cotter pin. Loosen nut attaching the wheel hub. Nut Cover Cotter Pin Remove rear wheel. (See page 13-4) Remove wheel hub nut, washer and wheel hub.
Page 204 . REAR WHEEL/SWING ARM/ HYDRAULIC BRAKE REAR AXLE REMOVAL Remove the rear wheel hub of the both rear wheels (See page 13-5). Remove the collars on the rear axle right and left side. Collars Drive Chain Relax the drive chain. (Refer to the “DRIVE CHAIN SLACK ADJUSTMENT”...
Page 205 . REAR WHEEL/SWING ARM/ HYDRAULIC BRAKE Remove the four bolts and rear axle hub. Bolts Axle Hub INSPECTION Replace it if the rear axle is scratched (excessively) or damage. Replace if splines and threads of the rear axle is wear or damage. Measure the rear axle run out.
Page 206 . REAR WHEEL/SWING ARM/ HYDRAULIC BRAKE Brake Drum Cover Inspect the driven sprocket. Replace sprocket if more than 1/4 teeth wear or bent teeth. Replace it if the brake disk is cracks or damage. Replace it if splines of the brake disk is wear or damage.
Page 207 . REAR WHEEL/SWING ARM/ HYDRAULIC BRAKE INSTALLATION Reverse the “REMOVAL” procedures. Install the rear axle hub. ＊ Apply grease onto the oil seal lips, bearings and bushes. ＊ At this time, the rear axle hub should not be tightened completely. Final tightening is done after the chain slack adjustment.
Page 208 . REAR WHEEL/SWING ARM/ HYDRAULIC BRAKE REAR SWING ARM REMOVAL Place the machine on a level place. Elevate the rear wheels by placing a suitable stand under the rear of frame. ＊ Support the machine securely so there is no danger of it falling over. Remove the rear wheels, rear hubs, rear axle and axle hub.
Page 209 . REAR WHEEL/SWING ARM/ HYDRAULIC BRAKE Check the swing arm side play by moving it from side to side. If side play noticeable, check the inner collar, bushing and thrust cover. Check the swing arm vertical movement by moving it up and down. If vertical movement is tight, binding or rough, to check the inner collar, bushing and thrust cover.
Page 210 . REAR WHEEL/SWING ARM/ HYDRAULIC BRAKE Swing Arm REAR SWING ARM REMOVAL Remove the nut and pivot shaft, then remove swing arm. Drive Chain Remove the three bolts and chain guard. Remove the drive chain. Chain Guard Bolts Remove thrust covers and collar. Thrust Covers 13-12...
Page 211 . REAR WHEEL/SWING ARM/ HYDRAULIC BRAKE INSPECTION Roll the axle on a flat surface to inspect the pivot shaft. Replace it if bends. ＊ Do not attempt to straighten a bent axle. Collar Chain Guide Inspect the swing arm. Replace it if crack, bend or damage. Inspect the thrust cover, chain guide, collar and bush.
Page 212 . REAR WHEEL/SWING ARM/ HYDRAULIC BRAKE ＊ This machine has a drive chain with small rubber O-rings between the chain plates. Steam cleaning, high-pressure washes, and certain solvent can damage these O-rings. Use only kerosene to clean the drive chain. O-ring INSTALLATION Reverse the “REMOVAL”...
Page 213 . REAR WHEEL/SWING ARM/ HYDRAULIC BRAKE HYDRAULIC BRAKE BRAKE FLUID CHANGE Place the machine on a level place and set the handlebar upright. Remove the two screws attaching the brake fluid reservoir cap. ＊ Use shop towels to cover plastic parts and coated surfaces to avoid damage caused by splash of brake fluid.
Page 214: Brake Pad/Disk
. REAR WHEEL/SWING ARM/ HYDRAULIC BRAKE BRAKE SYSTEM BLEEDING Connect a transparent hose to the bleed valve and fully apply the brake lever after continuously pull it several times. Then, loosen the bleed valve nut to bleed air from the brake system. Repeat these steps until the brake system is free of air.
Page 215: Brake Master Cylinder
. REAR WHEEL/SWING ARM/ HYDRAULIC BRAKE BRAKE DISK Measure the brake disk thickness. Service Limit: 3 mm (0.12 in) Measure the brake disk run out. Service Limit: 0.3 mm (0.12 in) Fluid Tube Bolt BRAKE MASTER CYLINDER REMOVAL Drain the brake fluid from the hydraulic brake system.
Page 216 . REAR WHEEL/SWING ARM/ HYDRAULIC BRAKE DISASSEMBLY Remove the piston rubber cover and snap ring from the brake master cylinder. Snap Ring Pliers Master Cylinder Remove the washer, main piston and spring from the brake master cylinder. Clean the inside of the master cylinder and brake reservoir with brake fluid.
Page 217 . REAR WHEEL/SWING ARM/ HYDRAULIC BRAKE ASSEMBLY Before assembly, apply brake fluid to all removed parts. ＊ • During assembly, the main piston and spring must be installed as a unit without exchange. • When assembling the piston, soak the cups in brake fluid for a while.
Page 218: Brake Caliper
. REAR WHEEL/SWING ARM/ HYDRAULIC BRAKE BRAKE CALIPER DISASSEMBLY Remove the brake caliper, brake pads and pad spring (See page 13-16). Place a clean container under the brake caliper and disconnect the brake fluid tube from the brake caliper. ＊ Be careful not to splash brake fluid on any coated surfaces.
Page 219 . REAR WHEEL/SWING ARM/ HYDRAULIC BRAKE INSPECTION Inspect the caliper cylinder wall and piston surface for scratch, corrosion or other damages. If any abnormal condition is noted, replace the caliper. ASSEMBLY Clean all removed parts. Apply silicon grease to the pistons and oil seals.
Page 220: Drum Brake
. REAR WHEEL/SWING ARM/ HYDRAULIC BRAKE Aligning The Fluid Tube With Groove INSTALLATION Connect the brake fluid tube to the brake caliper, aligning the fluid tube with groove in the caliper and tighten the fluid tube bolt. Torque: 35 N-m (3.5 kgf-m, 25 lbf-ft) Add the recommended brake fluid into the brake reservoir and bleed air from the brake system.
Page 221 . REAR WHEEL/SWING ARM/ HYDRAULIC BRAKE INSPECTION Inspect the inner surface of the brake drum is scratches, polish brake drum lightly and evenly with emery cloth. Measure the inside diameter of the brake drum. Service limit: 131 mm (5.24 in) Replace it if it is out of specification.
Page 222 . BATTERY/CHARGING SYSTEM/ A.C. GENERATOR __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ BATTER/CHARGING SYSTEM/ A.C. GENERATOR __________________________________________________________________________________ SERVICE INFORMATION------------------------------------------------ 14- 2 BATTERY REMOVAL ---------------------------------------------------- 14- 4 CHARGING SYSTEM ----------------------------------------------------- 14- 6 REGULATOR/RECTIFIER------------------------------------------------ 14- 7 A.C. GENERATOR CHARGING COIL ---------------------------------- 14- 8 A.C. GENERATOR LIGHTING COIL----------------------------------- 14- 8 RESISTOR INSPECTION ------------------------------------------------- 14- 8 A.C.
Page 223: Batter/Charging System
. BATTERY/CHARGING SYSTEM/ A.C. GENERATOR Regulator/Rectifier A.C. Generator CHARGING CIRCUIT Auto A.C. Generator Bystarter Battery Regulator/ 12V4AH Rectifier 14-1...
Page 224: A.c. Generator
. BATTERY/CHARGING SYSTEM/ A.C. GENERATOR SERVICE INFORMATIONN GENERAL INSTRUCTIONS The battery electrolyte (sulfuric acid) is poisonous and may seriously damage the skin and eyes. Avoid contact with skin, eyes, or clothing. In case of contact, flush with water and get prompt medical attention •...
Page 225 . BATTERY/CHARGING SYSTEM/ A.C. GENERATOR TORQUE VALUES A.C.G. flywheel nut 40 N-m (4 kgf-m, 29 lbf-ft) A.C.G. stator bolt 10 N-m (1 kgf-m, 7 lbf-ft) Pulser coil bolt 5 N-m (0.5 kgf-m, 3.6 lbf-ft) Cooling fan 8 N-m (0.8 kgf-m, 6 lbf-ft) SPECIAL TOOLS Flywheel puller A120E00001...
Page 226: Battery Removal
. BATTERY/CHARGING SYSTEM/ A.C. GENERATOR Bolts BATTERY REMOVAL Remove seat. (See page 2-3) Remove the battery cover, by removing the mount bolts. (Make sure the ignition switch is OFF.) Remove the battery by removing the bolts. Battery Cover Positive (+) Cable Negative (-) Cable First disconnect the battery negative (-) cable and then the positive (+) cable.
Page 227 . BATTERY/CHARGING SYSTEM/ A.C. GENERATOR CHARGING Connect the charger positive (+) cable to the battery positive (+) terminal. Power Lamp (Red) Connect the charger negative (-) cable to the battery negative (-) terminal. Charging Lamp Black (Green) • Keep flames and sparks away from a charging battery.
Page 228: Battery/Charging System/A
. BATTERY/CHARGING SYSTEM/ A.C. GENERATOR CHARGING SYSTEM SHORT CIRCUIT TEST Disconnect the ground wire from the battery and connect an ammeter across the battery negative (-) terminal and the ground wire. Turn the ignition switch OFF and check for short circuit. ＊...
Page 229: Regulator/Rectifier
. BATTERY/CHARGING SYSTEM/ A.C. GENERATOR REGULATOR/RECTIFIER MAIN HARNESS CIRCUIT Regulator/Rectifier INSPECTION Remove the regulator/rectifier 4P coupler and check for continuity between the wire harness terminals according to the following : Item (Wire Color) Judgment Between battery (red) Battery has and engine ground voltage Between ground (green) Continuity exists...
Page 230: Generator Charging Coil
. BATTERY/CHARGING SYSTEM/ A.C. GENERATOR Charging Coil Wire A.C. GENERATOR CHARGING COIL ＊ The inspection of A.C. generator charging coil can be made with the engine installed. INSPECTION Disconnect the A.C. generator 2P connector. Measure the resistance between the A.C. generator white wire and engine ground with an electric tester (YF-3501 tester).
Page 231 . BATTERY/CHARGING SYSTEM/ A.C. GENERATOR Cooling Fan Remove the cooling fan by removing the four cooling fan attaching bolts. Bolts Hold the flywheel with an universal holder. Remove the flywheel nut. Special tool Universal Holder A120E00017 Universal Holder Remove the A.C. generator flywheel using the flywheel puller.
Page 232 . BATTERY/CHARGING SYSTEM/ A.C. GENERATOR A.C. GNERATOR INSTALLATION Flywheel Woodruff Key 4 kgf-m Cooling Fan 0.8 kgf-m Fan Cover 0.5 kgf-m A.C. Generator Stator Wire Rubber Sleeve Reverse the A.C. GENERATOR REMOVE” procedures. Install the A.C. generator stator and pulser coil onto the right crankcase.
Page 233 . BATTERY/CHARGING SYSTEM/ A.C. GENERATOR Hold the flywheel with the universal holder and tighten the flywheel nut. Torque: 40 N-m (4 kgf-m, 29 lbf-ft) Special tool Universal Holder A120E00017 Install the cooling fan. Torque: 8 N-m (0.8 kgf-m, 6 lbf-ft) Install the fan cover and tighten bolts.
Page 234: Ignition System
. IGNITION SYSTEM __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ IGNITION SYSTEM __________________________________________________________________________________ SERVICE INFORMATION------------------------------------------------ 15- 3 CDI UNIT INSPECTION--------------------------------------------------- 15- 5 IGNITION COIL------------------------------------------------------------- 15- 7 PULSER COIL --------------------------------------------------------------- 15- 8 IGNITION TIMING INSPECTION--------------------------------------- 15- 8 15-0...
Page 235: Ignition System
. IGNITION SYSTEM Ignition Coil A.C. Generator/ Pulser Coil Spark Plug 15-1...
Page 236 . IGNITION SYSTEM IGNITION CIRCUIT (90cc/70cc/50cc-4T) IGNITION CIRCUIT (50cc-2T) 15-2...
Page 237: Service Information
. IGNITION SYSTEM SERVICE INFORMATION GENERAL INSTRUCTIONS • Check the ignition system according to the sequence specified in the Troubleshooting. • The ignition system adopts ignition unit, change gear control and the ignition timing cannot be adjusted. • If the timing is incorrect, inspect the ignition unit, A.C. generator, change gear control and replace any faulty parts.
Page 238 . IGNITION SYSTEM TROUBLESHOOTING High voltage too low No high voltage • Weak battery or low engine speed • Faulty ignition switch • Loose ignition system connection • Faulty ignition unit • Faulty ignition unit • Poorly connected or broken ignition unit ground wire •...
Page 239: Cdi Unit Inspection
. IGNITION SYSTEM CDI Unit CDI UNIT INSPECTION Remove seat. ( 2-3) Disconnect the CDI coupler and remove the CDI unit. Measure the resistance between the terminals using the electric tester. ＊ • Due to the semiconductor in circuit, it is necessary to use a specified tester for accurate testing.
Page 240 . IGNITION SYSTEM Black/Yellow Black 90cc (ON ROAD) Unit: MΩ Probe⊕ Black/ Blue/ Black Green Yellow Yellow (-)Probe ∞ ∞ ∞ Black Black/ ∞ ∞ ∞ Yellow Blue/ ∞ ∞ ∞ Yellow Green Blue/Yellow Green 6.1~6.8 6.1~6.8 6.1~6.8 Note: The readings in this table are taken with a YF-3501 Tester.
Page 241: Ignition Coil
. IGNITION SYSTEM IGNITION COIL REMOVAL Remove the spark plug cap. Disconnect the ignition coil wires and remove the ignition coil bolt and ignition coil. Ignition Coil INSPECTION CONTINUITY TEST ＊ The CDI unit is not adjustable. If the timing is incorrect, inspect the CDI unit, pulser coil and A.C.
Page 242: Pulser Coil
. IGNITION SYSTEM PULSER COIL INSPECTION ＊ This test is performed with the stator installed in the engine. Disconnect the A.C. generator connector. Measure the pulser coil resistance between the blue/yellow and green wire terminals. Pulser Coil Lead Resistance: 90cc/70cc/50cc-4-T: 100～140Ω/20°C 50cc-2T: 80～160Ω/20°C Note: The readings in this table are taken...
Page 243: Starting System
. STARTING SYSTEM __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ STARTING SYSTEM __________________________________________________________________________________ SERVICE INFORMATION------------------------------------------------ 16- 2 STARTER MOTOR --------------------------------------------------------- 16- 3 STARTER RELAY---------------------------------------------------------- 16- 6 STARTER CLUTCH (90cc) ----------------------------------------------- 16- 7 STARTER PINION (70cc/50cc-4T/50cc-2T)---------------------------- 16- 9 16-0...
Page 244 . STARTING SYSTEM Starter Motor STARTING CIRCUIT Starter Relay Fuse Ignition Switch Start Stoplight Switch Battery Starter Motor Front Rear Stop Switches 16-1...
Page 245 . STARTING SYSTEM SERVICE INFORMATION GENERAL INSTRUCTIONS • The removal of starter motor can be accomplished with the engine installed. TROUBLESHOOTING Starter motor won‘t turn Lack of power • Fuse burned out • Weak battery • Weak battery • Loose wire or connection •...
Page 246: Starter Motor
. STARTING SYSTEM Starter Motor STARTER MOTOR REMOVAL ＊ Before removing the starter motor, turn the ignition switch OFF and remove the battery ground. Then, turn on the ignition switch and push the starter button to see if the starter motor operates properly.
Page 247 . STARTING SYSTEM STARTER MOTOR CASE CONTINUITY CHECK Check to confirm that there is no continuity between the starter motor wire terminal and the motor front cover. Also check for the continuity between the wire terminal and each brush. Replace if necessary. Wire Terminal Measure the length of the brushes.
Page 248 . STARTING SYSTEM Front Cover Commutator ASSEMBLY Apply grease to the dust seal in the front cover. Install the brushes onto the brush holders. Apply a thin coat of grease to the two ends of the armature shaft. Insert the commutator into the front cover. ＊...
Page 249 . STARTING SYSTEM Starter Relay STARTER RELAY INSPECTION Remove the seat. (Refer to the chapter 2) Turn the ignition switch ON and the starter relay is normal if you hear a click when the starter button is depressed. If there is no click sound: •...
Page 250 . STARTING SYSTEM STARTER ONE-WAY CLUTCH/ Reduction Gear Case STARTER PINION (90cc) REMOVAL Remove the left crankcase cover and drive pulley face. (Refer to chapter 9) Remove the reduction gear case. Starter One-way Clutch Drive Nut Flywheel Lock Nut Socket Wrench Hold flywheel using universal holder (refer to chapter 14) while remove the starter one- way clutch drive nut with the special tool.
Page 251 . STARTING SYSTEM INSTALLATION Install each washer to the top and bottom of Starter Gear Shaft Reduction Gear the reduction gear. Apply grease to the reduction gear shaft forcing part. Then, install in the reverse order of removal. Reduction Gear Case Washers INSPECTION Inspect the starter one-way clutch drive gear...
Page 252 . STARTING SYSTEM Check starter clutch operation. Clutch operation checking steps: Install the starter wheel gear to the starter clutch, and hold the starter clutch. When turning the wheel gear clockwise (1) the starter clutch and the wheel gear should be engaged. If not, the starter clutch is faulty.
Page 253 . STARTING SYSTEM Starter Pinion STARTER PINION (70cc/50cc- 50cc-2T 4T/50cc-2T) REMOVAL Remove the left crankcase cover. Remove the drive pulley. (Refer to chapter 9) Remove the starter pinion cover (50cc-2T only). Remove the starter pinion. Starter Pinion Cover (50cc-2T only) Starter Pinion 70cc/50cc-4T Shaft Forcing Parts...
Page 254: Bulbs Removal/Instrument/Horn
. BULBS REMOVAL/INSTRUMENT/HORN __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ BULBS REMOVAL/INSTRUMENT/HORN __________________________________________________________________________________ BULBS REMOVAL--------------------------------------------------------- 17- 1 INSTRUMENT (ON ROAD ONLY) ------------------------------------- 17- 4 HORN (ON ROAD ONLY) ------------------------------------------------ 17- 4 17-0...
Page 255 . BULBS REMOVAL/INSTRUMENT/HORN Headlight Wire Coupler BULBS REMOVAL HEADLIGHT (ON ROAD ONLY) Remove the front fender. (See page 2-5) Disconnect the headlight wire coupler. Remove the rubber boot from the bulb socket. Relax the lock clip to remove the bulb and replace with a new one.
Page 256 . BULBS REMOVAL/INSTRUMENT/HORN Bulb Socket Bulb INDICATOR LIGHTS Remove the handlebar cover (see page 2-3) and raise it. Remove the bulb sockets by pulling them out. Pull the bulb out of the socket and replace it with a new one. Installation is in the reverse order of removal.
Page 257 . BULBS REMOVAL/INSTRUMENT/HORN Install the bulb socket, aligning the bulb socket groove with the turn signal case tab. Install the turn signal lens, aligning the turn signal lens groove with the turn signal case tab. Bule Screw REAR TURN SIGNAL LIGHT (ON ROAD ONLY) Remove the screw and remove the turn signal light lens.
Page 258 . BULBS REMOVAL/INSTRUMENT/HORN Screws INSTRUMENT (ON ROAD) REMOVAL Remove the handlebar cover. (See page 2-3) Disconnect the meter connectors. Remove the two screws and then remove the instrument. Installation is in the reverse order of removal. Instrument Connectors Horn HORN (ON ROAD) Connectors REMOVAL Disconnect the horn wire connectors.

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KYMCO Mongoose 90 Service Manual

Preface

Frame Covers/Exhaust Muffler

3. Inspection/Adjustment 3

4. Lubrication System 4

5. Fuel System 5

Cylinder Head/Valves (90Cc/70Cc/50Cc-4T)

Cylinder Head/Valves

(90Cc/70Cc/50Cc-4T)

9.Drive and Driven Pulleys 9

Front Wheel/Front Brake/ Front Suspension\Steering System

13. Rear Wheel/Swing Arm/ Hydraulic Brake 13 13

14. Battery/Charging System/ A.C. Generator 14

Batter/Charging System

A.C. Generator

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