Honda CM 185T 1981 Manual
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Honda CM 185T 1981 Manual

Honda CM 185T 1981 Manual

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G E N E R A L
SPECIFICATIONS
ITEM
DIMENSIONS
Overall length
Overall w i d t h
Overall height
Wheelbase
Seat height
Foot peg height
Dry weight
F R A M E
Type
F. suspension, travel
R. suspension, travel
F. tire size, pressure
R. tire size, pressure
F. brake, lining swept area
R. brake lining, swept area
Fuel capacity
Fuel reserve capacity
Caster angle
Trail
Front fork oil capacity
ENGINE
Type
Cylinder arrangement
Bore and stroke
Displacement
Compression ratio
Valve train
Maximum horsepower
Maximum torque
Oil capacity
Lubrication system
Air f i l t r a t i o n
Cylinder compression
Intake valve
Opens
Closes
Exhaust valve
Opens
Closes
Valve clearance
Idle speed
1-2
I N F O R M A T I O N
1,960 mm (77.2 in.)
830 mm (32.7 in.)
1,130 mm (44.5 in.)
1,280 mm (50.4 in.)
730 mm (28.7 in.)
180 mm ( 7.1 in.)
124 kg (273 lbs.)
Diamond
Telescopic fork
115 mm (4.53 in.)
Swing arm
64 mm (2.53 in.)
3 . 0 0 - 1 7 (4PR)
1.75 k g / c m
2
(25 psi)
3.50—16 (4PR)
2.25 k g / c m
2
(32 psi)
Internal expanding shoes,
110 c m
2
(17.05 sq. in.)
Internal expanding shoes,
123 c m
2
(19.07 sq. in.)
10.5 liters (2.8 U.S. gal.)
3.0 liters (0.8 U.S. gal.)
62°
92 mm (3.6 in.)
125 cc (4.2 oz), 98 cc (3.3 oz) at draining
Air cooled 4-stroke
Parallel t w i n 20° inclined f r o m vertical
5 3 x 4 1 mm (2.09 x 1.61 in.)
181 cc ( 1 1 . 0 3 c u . in.)
9.0 : 1
Chain drive overhead camshaft
15.0 BHP/9,500 rpm
1.28 kg-m (9.26 ft-lb.)/7,000 rpm
1.5 liters (1.6 U.S. qt.)
Pressure and wet sump
Oiled polyurethane foam
12.0 ± 2.0 k g / c m
2
(170 ± 28 psi)
- 3 ° (B.T.D.C.) at 1mm lift. 45°
(B.T.D.C.) at 0 lift
34°
(A.B.D.C.) at 1mm lift, 97° (A.B.D.C.) at 0 lift
33°
(B.B.D.C.) at 1 mm lift, 9 4 ° (B.B.D.C.) at 0 lift
- 4 ° (A.T.D.C.) at 1mm lift, 49° (A.T.D.C.) at 0 lift
I N :
0.05 mm (0.002 in.)
EX:
0.05 mm (0.002 in.)
1,200 ± 100 rpm
Date of Issue: December, 1977
© H O N D A MOTOR CO., L T D .

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  • Page 1 G E N E R A L I N F O R M A T I O N SPECIFICATIONS ITEM DIMENSIONS Overall length 1,960 mm (77.2 in.) Overall w i d t h 830 mm (32.7 in.) Overall height 1,130 mm (44.5 in.) Wheelbase 1,280 mm (50.4 in.) Seat height...
  • Page 2 3/32 cp T u r n signal light 21 cp Speedometer light 2 cp Neutral indicator light 2 cp Turn signal indicator light 1 cp High beam indicator light 1 cp Date of Issue: December, 1977 © HONDA MOTOR CO., LTD.
  • Page 3 GENERAL INFORMATION SERVICE DATA E N G I N E m m (in.) ITEM S T A N D A R D SERVICE L I M I T Cylinder head warpage 0.1 (0.0039) Cylinder head height 7 2 . 7 5 - 7 2 . 8 5 (2.8642-2.8681) 72.6 (2.8583) Cylinder I.D.
  • Page 4 HONDA. CM 1 8 5 T GENERAL INFORMATION F R A M E m m (in.) ITEM S T A N D A R D SERVICE L I M I T Front/rear axle bend 0.2 (0.0079) Front brake d r u m I.D.
  • Page 5 GENERAL INFORMATION TORQUE VALUES E N G I N E T I G H T E N I N G POINT Q'TY T H R E A D D I A (mm) TORQUE kg-m (ft-lb.) Crankshaft holder bolt nut 1 . 0 - 1 . 4 ( 7 . 2 - 1 0 . 1 ) Cylinder head nut 1 .
  • Page 6 HONDA CM 1 8 5 T GENERAL INFORMATION SPECIAL TOOLS S P E C I A L T O O L S T O O L N A M E TOOL NO. A P P L I C A T I O N REF.
  • Page 7 GENERAL INFORMATION W I R I N G D I A G R A M S 1 - 8 Date of Issue: December, 1977 © H O N D A M O T O R CO., L T D .
  • Page 8 GENERAL INFORMATION 1 - 8 Date of Issue: December, 1977 © HONDA MOTOR CO., LTD.
  • Page 9 GENERAL INFORMATION WIRING DIAGRAMS 1 - 8 Date of Issue: December, 1977 © HONDA MOTOR CO., LTD.
  • Page 10 T H R O T T L E CABLE CLUTCH CABLE SPEEDOMETER C A B L E CHOKE CABLE WIRE BANDS NOTE Clamp stop switch wire and starting switch wire. Date of Issue: December, 1977 © HONDA MOTOR CO.. L T D .
  • Page 11 GENERAL INFORMATION • WIRE HARNESSES WIRE B A N D NOTE Clamp wire harness, T U R N SIGNAL SWITCH WIRE clutch cable and L I G H T I N G SWITCH WIRE choke cable. BATTERY WHITE TAPE S T A R T I N G MOTOR NOTE Install the white tape of the wire harness into the center...
  • Page 12 A N D S T A R T I N G MOTOR OF THE LEFT CRANKCASE COVER. • TURN SIGNAL AND TAILLIGHT WIRES WIRE CORD GROMMET NOTE Date of Issue: December, 1977 1-11 © HONDA MOTOR CO., L T D .
  • Page 13 I N T A K E PIPE A I R CLEANER BREATHER SEPARATOR DRAIN TUBE D R A I N P L U G FRESH A I R BLOW-BY GAS Date of Issue: December, 1977 1-12 © HONDA MOTOR CO., L T D .

  • Page 14: Table Of Contents

    I N I T I A L SERVICE PERIOD 200 miles (300 km) (4) FOR HIGHER ODOMETER READINGS, REPEAT AT T H E FREQUENCY I N T E R V A L ESTABLISHED HERE. Date of Issue: December, 1977 1-13 © HONDA MOTOR CO., L T D .
  • Page 15 GENERAL INFORMATION EMISSION CONTROL INFORMATION LABEL An Emission Control Information Label is located on the CM185T'S front frame downtube. It contains basic tune-up specifications for CM185T's manufactured after December 3 1 , 1977. 1-14 Date of Issue: December, 1977 © H O N D A MOTOR CO., LTD.
  • Page 16 3. Worn piston rings Low Oil Pressure 1. Plugged oil pick-up screen 2. Oil pump w o r n 3. External oil leaks 4. Oil level low Date of Issue: December, 1977 © HONDA MOTOR CO., L T D .
  • Page 17 Fill the crankcase w i t h specified engine o i l , and start the engine. Stop the engine, check the oil level and inspect SCREEN HOLDER for oil leaks. Date of Issue: December, 1977 © HONDA MOTOR CO.. LTD.
  • Page 18 LUBRICATION L U B R I C A T I O N P O I N T S Date of Issue: December, 1977 2 - 3 © HONDA MOTOR CO., LTD.
  • Page 19 LUBRICATION LUBRICATION DIAGRAM O I L T H R O U G H PLATE O I L PUMP D R I V E GEAR O I L T H R O U G H O l L PUMP O I L SCREEN Date of Issue: December, 1977 ©...
  • Page 20 4 . 0 - 5 . 0 kg-m ( 2 8 . 9 - 3 6 . 2 ft-lb.) Spoke nipples: 0 . 2 - 0 . 3 5 kg-m ( 1 . 4 - 2 . 5 ft-lb.) Date of Issue: December, 1977 © HONDA MOTOR CO., L T D .
  • Page 21 Gear oil solvent. excess excess oil. (SAE 80-90) solvent. install the air cleaner element. Install the holder, set spring and air cleaner cover. Install the left side cover. Date of Issue: December. 1977 © HONDA MOTOR CO., L T D .

  • Page 22: Crankcase Breather

    INSPECTION/ADJUSTMENT CRANKCASE BREATHER Remove drain plug f r o m tube, drain deposits. Reinstall drain plug. NOTE Service more frequently when driven in rainy conditions or at wide open throttle, or if deposit level can be seen in the transparent section of drain tube. FUEL LINES have deterioration, Replace any parts which...

  • Page 23: V A L V E Clearance

    Reinstall cylinder head cover and generator rotor cover. TORQUE: CYLINDER HEAD COVER BOLTS 0 . 8 - 1 . 2 kg-m ( 5 . 8 - 7 . 8 ft-lb.) Date of Issue: December. 1977 © HONDA MOTOR CO., L T D .

  • Page 24: Ignition Timing

    INSPECTION/ADJUSTMENT CONTACT POINT GAP Clean the point contact surfaces with an elec- trical conîact cleaner to remove any oil film or airt. If rhe surfaces are level but grayish In color or slightly pitted, file them with a flexible point file lightly. If the points have à...
  • Page 25 If the index mark is out of the advance marks, check the spark advance operation and replace. INDEX M A R K A D V A N C E MARKS Date of Issue: December, 1977 © HONDA MOTOR CO., L T D .

  • Page 26: Cam Chain Tension

    INSPECTION/ADJUSTMENT CAM CHAIN TENSION Stop the engine and remove the generator TENSIONER rotor cover. Rotate the generator rotor counter- A R M clockwise and align the " T 1 " mark on the spark advancer w i t h index mark on the left crank case cover.

  • Page 27: Carburetor Idle Speed

    INSPECTION/ADJUSTMENT Minor adjustments are performed w i t h the upper adjuster. Adjust w i t h the throttle grip in the closed position. Recheck the operation of the t h r o t t l e grip. CARBURETOR CHOKE Check the choke knob for smooth operation.
  • Page 28 Improper valve adjustment • Blown cylinder head gasket • Piston ring wear High compression can be caused by: • Carbon deposits in the combustion chamber or on piston head. Date of Issue: December, 1977 ® HONDA MOTOR CO., L T D .
  • Page 29 Both chain and sprockets must be in good condition, or the new replace- ment chain or sprockets will wear rapidly. Date of Issue: December, 1977 3-10 © HONDA MOTOR CO.. L T D .

  • Page 30: Battery

    INSPECTION/ADJUSTMENT Lubricate the drive chain. Saturate each chain link joint. NOTE Commercial aerosol type drive chain lu- bricants are recommended.' Install the drive chain. Install the master link. Install the master link retaining clip so that the closed end faces the direction of forward wheel rotation.

  • Page 31: Brake System

    Perform minor adjustments w i t h the upper adjuster. Loosen the lock nut and t u r n the adjuster to obtain the specified free play. Tighten the lock nut. Date of Issue: December, 1977 3-12 © HONDA MOTOR CO.. L T D .
  • Page 32 INSPECTION/ADJUSTMENT • B R A K E P E D A L H E I G H T Loosen the lock nut and adjust the pedal height w i t h the stopper bolt. Tighten the lock nut securely. • B R A K E P E D A L F R E E P L A Y NOTE Adjust the rear brake pedal free play...
  • Page 33 The stoplight should come on when the brake pedal is depressed 20 mm (3/4 in.) f r o m the standard position. Adjust by turning switch adjusting nut. Date of Issue: December, 1977 3-14 © HONDA MOTOR CO., L T D .

  • Page 34: Headlight Aim

    ( 3 / 8 - 3 / 4 in.) Major adjustments are made at the lower adjuster. Loosen the lock nut and t u r n adjuster. Date of Issue: December, 1977 3-15 © HONDA MOTOR CO., L T D .

  • Page 35: Side Stand

    2 - 3 kg (4.4—6.6 lb.) when pulling the side stand lower end using a spring scale. GOOD NO GOOD WEAR LINE Date of Issue: December, 1977 3-16 © HONDA MOTOR CO., L T D .

  • Page 36: Suspension

    1.75 (25) capacity Rear: load 2.25 (32) Vehicle capacity load 135 kg (300 lbs.) limit F r o n t 3.00-17-4PR Tire size Rear: 3.50-16-4PR Date of Issue: December, 1977 3-17 © HONDA MOTOR CO.. L T D .

  • Page 37: Steering Head Bearing

    ^ f e y C M 1 8 5 T INSPECTION/ADJUSTMENT WHEEL SPOKE RETIGHTENING Retighten the wheel spokes periodically. T I G H T E N I N G TORQUE: 0 . 2 - 0 . 3 5 kg-m ( 1 . 4 - 2 . 5 ft-lb.) STEERING HEAD BEARING NOTE Check...
  • Page 38 CM185T B E G I N N I N G W I T H F/N 2000014 The frame serial number is on the right side of the steering The legal vehicle identification number (VIN) is on the The engine serial number is on the left lower side of the The carburetor identification number is on the right of crankcase.
  • Page 39 4. CARBURETOR SERVICE INFORMATION 4 - 1 4 - 2 TROUBLESHOOTING 4 - 3 CARBURETOR REMOVAL 4 - 3 CARBURETOR TOP DISASSEMBLY 4—4 THROTTLE VALVE DISASSEMBLY 4 - 4 FLOAT, FLOAT VALVE AND JETS 4 - 6 FLOAT LEVEL ADJUSTMENT 4 - 6 THROTTLE VALVE ASSEMBLY...
  • Page 40 Float level too high Carburetor air jets clogged Pilot screw misadjusted Air cleaner clogged Misfiring during Acceleration Incorrect carburetor air/fuel mixture Backfiring Incorrect carburetor air/fuel mixture Carburetor malfunction Date of Issue: December, 1977 © HONDA MOTOR CO.. L T D .
  • Page 41 CARBURETOR CARBURETOR REMOVAL Turn the fuel valve " O F F " and disconnect the fuel tube. Remove the choke cable after loosening the screw. Loosen the screw securing the carburetor band and remove setting nuts. Unscrew carburetor cap, pull the throttle valve out and remove the carburetor.
  • Page 42 Pry off the float arm pin w i t h a pair of pliers. Remove the float and float valve. Inspect the float valve surface for wear or damage. Date of Issue: December, 1977 © HONDA MOTOR CO., L T D .
  • Page 43 Install the pilot screw, the needle jet holder NEEDLE JET HOLDER M A I N JET and the main jet. NOTE Do not damage the jets at time of as- sembly. Date of Issue: December, 1977 © HONDA MOTOR CO., L T D .
  • Page 44 Install the needle cap plate on the lower position of throttle valve completely. Install the throttle cable and spring. Install the t h r o t t l e valve. Date of Issue: December, 1977 © HONDA MOTOR CO., L T D .
  • Page 45 Clamp the choke cable end on the cable setting plate. • After assembly, perform the follow- ing adjustments. Throttle grip free play (See page 3.7) Idle speed adjustment (See page 3.8) Date of Issue: December, 1977 © HONDA MOTOR CO., L T D .
  • Page 46 Return the pilot screw to the factor)' pre-set position and readjust the idle Adjust the idle speed at high altitude to speed to 1,200 ± J 00 rpm. ensure proper high altitude operation. Date of Issue: December, 1977 © HONDA MOTOR CO., L T D .
  • Page 47 CARBURETOR...
  • Page 48 ENGINE REMOVAL AND INSTALLATION SERVICE INFORMATION 5 - 1 ENGINE REMOVAL 5 - 2 ENGINE INSTALLATION 5 - 6 SERVICE INFORMATION • WORKING PRACTICE A jack or other adjustable support is required to support and maneuver the engine. The carburetor assy, may be detached to speed engine removal. Works requiring engine removal: Cylinder head and valves Section 6...
  • Page 49 Disconnect the breather tube and remove the plug cap. Remove the starter magnetic switch and the turn signal relay. Disconnect the stop switch wires and the bat- tery cords. Remove the battery. Date of Issue: December, 1977 © HONDA MOTOR CO., LTD.
  • Page 50 C M 1 8 5 T ENGINE REMOVAL AND INSTALLATION Disconnect the clutch cable at the lower ad- juster. Disconnect the starting motor cable at the starting motor. Disconnect the coupler of the silicon rectifier and condenser cord. Loosen the air cleaner tube band and remove the air cleaner case w i t h i n air cleaner element.
  • Page 51 Loosen the foot rest right side setting bolts. WARNING Place the frame body on the rigid rack before removing the foot rests. Remove the through bolts and remove the f o o t rests. Date of Issue: December, 1977 © HONDA MOTOR CO., L T D .
  • Page 52 C M 1 85T ENGINE REMOVAL AND INSTALLATION Pry off the drive chain clip and remove the master link. Remove the drive chain. Support the engine w i t h a jack or other ad- justable support under the engine. Remove the four hanger bolts and front engine bracket.
  • Page 53 8 m m F L A N G E BOLTS 10mm F L A N G E BOLTS FRONT HANGER BRACKET 8 m m F L A N G E BOLTS Date of Issue: December, 1977 © HONDA MOTOR CO., L T D .
  • Page 54 ENGINE REMOVAL AND INSTALLATION Date of Issue: December, 1977 © H O N D A MOTOR CO., L T D .
  • Page 55 CYLINDER HEAD/ VALVES SERVICE INFORMATION 6 - 1 TROUBLESHOOTING 6 - 3 ROCKER ARM/CAMSHAFT REMOVAL 6 - 4 CYLINDER HEAD REMOVAL 6 - 8 CYLINDER HEAD DISASSEMBLY 6 - 8 VALVE GUIDE REPLACEMENT 6 - 1 1 VALVE SEAT INSPECTION/RE FACING 6 - 1 2 CYLINDER HEAD ASSEMBLY 6 - 1 6...
  • Page 56 CYLINDER HEAD/VALVES • SERVICE DATA Date of Issue: December, 1977 © HONDA MOTOR CO., L T D .
  • Page 57 1. Incorrect valve adjustment 2. Sticking valve or broken valve spring 3. Damaged rocker arm or camshaft 4. Worn or damaged camshaft sprocket 5. Slacken or worn cam chain Date of Issue: December, 1977 © HONDA MOTOR CO., L T D .
  • Page 58 CYLINDER HEAD/VALVES ROCKER ARM/ CAMSHAFT REMOVAL Remove the generator cover and the cylinder head cover and unscrew the camshaft holder nuts. CAUTION Perform this operation while the engine is cold to prevent warpage due to heat. Loosen the cylinder head hold-down holts in the sequence shown in steps 2-3.
  • Page 59 NOTE Suspend the cam chain w i t h a piece of wire to prevent it f r o m falling into the cylinder. Date of Issue: December, 1977 © HONDA MOTOR CO., L T D .
  • Page 60 Measure the I.D. of the camshaft bushing. D A M A G E OR WEAR I.D. SERVICE L I M I T : 20.20 mm (0.7965 in.) Date of Issue: December, 1977 © HONDA MOTOR CO., L T D .
  • Page 61 CYLINDER HEAD/VALVES • CAMSHAFT INSPECTION RUNOUT SERVICE L I M I T : Check the camshaft runout w i t h a dial indica- 0.05 mm (0.0020 in.) tor. Support both ends of the camshaft b locks. Take 1/2 of total indicator reading. Inspect the camshaft journal for wear or dam- age.
  • Page 62 CYLINDER HEAD/VALVES CYLINDER HEAD REMOVAL Remove the intake manifold. Remove the cam chain tensioner bolt and remove the cylinder head. CAUTION To prevent damage to the cylinder head, pry only at the cutout of cylinder gasket. Remove the cylinder gasket, dowel pins and O-rings.
  • Page 63 CYLINDER HEAD/VALVES Remove carbon deposits from the combustion chamber. Clean off the head gasket surfaces. NOTE Avoid damaging the gasket surfaces. Gasket w i l l come off easier if soaked in solvent. • CYLINDER HEAD INSPECTION Check the spark plug hole and valve areas for cracks.
  • Page 64 NOTE Reface valve seats whenever the valve guides are replaced. Date of Issue: December, 1977 6-10 © HONDA MOTOR CO., L T D .
  • Page 65 CYLINDER HEAD/VALVES VALVE GUIDE REPLACEMENT DRIVER A N D REMOVER 5.5 mm PILOT 5.5 mm Support the cylinder head and drive out the guide f r o m the valve port. NOTE When driving out the valve guide, do not damage the head.
  • Page 66 CYLINDER HEAD/VALVES VALVE SEAT INSPECTION/ REFACING Clean all intake and exhaust valves thoroughly to remove carbon deposits. Apply a light coat of valve lapping compound to each valve face. Lap each valve and seat using a rubber hose or other hand-lapping tool. Remove the valve and inspect the face.
  • Page 67 VALVE SEAT GRINDER WARNING Use adequate eye protection when using the valve seat grinder. MOVE UP AND DOWN LIGHTLY PILOT BAR A Date of Issue: December. 1977 6-13 © HONDA MOTOR CO., L T D .
  • Page 68 CYLINDER HEAD/VALVES • TOP CUT Using a 37.5" grinding stone, remove 1/4 of the existing valve seat material. M A T E R I A L REMOVED Inspect the area of the removed valve seat. OLD SEAT W I D T H •...
  • Page 69 CYLINDER HEAD/VALVES Check the contact between the valve and valve seat w i t h Prussian Blue. T O P C U T M A T E R I A L REMOVED If the contact area on the valve face is too high, the seat must be lowered, w i t h a 37.5°...
  • Page 70 ^ f e / C M 1 8 5 T CYLINDER HEAD/VALVES CYLINDER HEAD ASSEMBLY NOTE Replace the valve stem seals when dis- assembling. C Y L I N D E R HEAD Lubricate each valve stem w i t h oil and insert the valve into the valve guide.
  • Page 71 CYLINDER HEAD/VALVES CYLINDER HEAD INSTALLATION Clean the cylinder head gasket surfaces of any gasket material. Install the O-rings, dowel pins and a new gasket. Loosen, the cam chain tensioner lock nut and pull the tensioner up fully. Retighten the lock nut.
  • Page 72 CYLINDER HEAD/VALVES CAMSHAFT AND ROCKER ARM INSTALLATION Assemble rocker arms and springs by installing the rocker arm shaft into the cam- shaft holder. NOTE • A p p l y a thin coat of oil to the shafts before assembly. •...
  • Page 73 CYLINDER HEAD/VALVES Insert the knock pins of the camshaft bushings into the grooves of the cylinder head. (Insert left and right sides securely.) Turn the camshaft so that the cutout faces the intake side and positions it parallel to the cylinder head surface.
  • Page 74 1 . 0 - 1 . 4 kg-m ( 7 . 2 - 1 0 . 1 ft-lb.) NOTE Tighten an X pattern in 2-3 steps. Date of Issue: December, 1977 6-20 © HONDA MOTOR CO., L T D .
  • Page 75 CYLINDER HEAD/VALVES Fill the oil pockets in the cylinder head w i t h oil so that the cam lobes are submerged. Adjust valve clearance, Pages 3-4. Adjust cam chain tensioner. Page 3-7. Inspect the cylinder head cover gasket for damage or deterioration.
  • Page 76 CYLINDER HEAD/VALVES T O R Q U E : 0 . 8 - 1 . 2 kg-m ( 5 . 8 - 8 . 7 ft-lb.) TORQUE: 1 . 6 - 2 . 0 kg-m ( 1 1 . 6 - 1 4 . 5 ft-lb.) TORQUE: 1 .
  • Page 77 «TSST C Y L I N D E R / P I S T O N 7 - 1 SERVICE INFORMATION TROUBLESHOOTING 7 - 2 7 - 3 CYLINDER REMOVAL 7 - 4 PISTON REMOVAL PISTON INSTALLATION 7 - 9 CYLINDER INSTALLATION 7 - 9 SERVICE INFORMATION...
  • Page 78 CYLINDER/PISTON TROUBLESHOOTING Low or Uneven Compression 1. Worn cylinder or piston rings Compression Too High 1. Excessive carbon deposits on pistons Excessive Smoke 1. Worn cylinder and piston rings 2. Improperly installed piston rings 3. Damaged piston or cylinder Engine Overheating 1.
  • Page 79 CYLINDER/PISTON CYLINDER REMOVAL Remove the cylinder head (Refer to Section Pry off the cam chain tensioner clip and pin. NOTE Do not drop the clip and pin into the crankcase. Remove the tensioner lock nut, washer and O-ring. Remove the tensioner base. Remove the cylinder.
  • Page 80 Press the piston pin out of the piston. NOTE Mark the pistons to indicate the cylinder positions. PISTON PIN CLIP Date of Issue: December, 1977 © HONDA MOTOR CO., L T D .
  • Page 81 CYLINDER/PISTON • PISTON/PISTON RING CLEARANCE SERVICE L I M I T : INSPECTION 0.12 mm (0.0048 in.) Inspect the piston ring-to-groove clearance. PISTON RING Remove the piston rings. NOTE Mark the rings so that they can be re- turned to their original location. Inspect the piston for damage and cracks.
  • Page 82 CYLINDER/PISTON Measure the piston O.D. at the skirt. O . D . S E R V I C E LIMIT: Measurements should be taken at a point 10 52.86 mm (2.0811 in.) mm ( 0 . 4 in.) f r o m the b o t t o m . Calculate the cylinder-to-piston clearance.
  • Page 83 CYLINDER/PISTON Measure the piston pin O.D. O.D. SERVICE L I M I T . Measure at front, center and rear and in two 13.98 mm (0.5504 In.) directions across f r o m each other. Determine the piston-to-piston pin clearance. SERVICE L I M I T : 0.04 mm (0.0016 in.) Measure each piston ring thickness.
  • Page 84 After installing each ring on the piston, turn the rings by hand to check for smooth movement. • When installing a new ring, check that it fits smoothly into the ring groove and does not bind. Date of Issue: December, 1977 © HONDA MOTOR CO., L T D .
  • Page 85 CYLINDER/PISTON PISTON INSTALLATION Install the piston and piston pins. NOTE • Position the " • " mark on the piston to the exhaust valve side. • Install the pistons in their original locations. Use new piston pin clips when assembling. PISTON PIN CLIP NOTE Install w i t h the piston pin clip end gap...
  • Page 86 A M C H A I N ENSIONER BOLT Install the dowel pins, O-rings and the gasket. Install the cylinder head (Refer to Section 6 ) . Date of Issue: December, 1977 7-10 © HONDA MOTOR CO., L T D .
  • Page 87 CYLINDER/PISTON Date of Issue: December, 1977 © HONDA MOTOR CO., L T D .
  • Page 88 18.020-18.041 mm ( 0 . 7 0 9 4 - 0 . 7 1 0 3 in.) 18.07 mm (0.7114 in.) Spindle O.D. 1 7 . 9 5 9 - 1 7 . 9 8 0 mm (0.7070-0.7079 in.) 17.93 mm (0.7059 in.) Date of Issue: December, 1977 © HONDA MOTOR CO., L T D .
  • Page 89 2. Plugged oil filter screen, gallery or metering orifice No Oil Pressure 1. Oil pump drive gear broken 2. Oil pump assy broken 3. Leaks from oil circuit Date of Issue: December, 1977 © HONDA MOTOR CO., L T D .
  • Page 90 Remove the four lifter plate setting bolts, the lifter plate and the four clutch springs. NOTE Loosen the bolts in an X pattern in two or more steps. Date of Issue: December, 1977 © HONDA MOTOR CO.. L T D .
  • Page 91 Pry off the 20 mm circlip. Remove the clutch center, friction disc plates, FRICTION DISC clutch plates and clutch pressure plate. CLUTCH PLATE CLUTCH CENTER CLUTCH PRESSURE PLATE Date of Issue: December. 1977 © HONDA MOTOR CO., L T D .
  • Page 92 CLUTCH/OIL PUMP/GEAR SHIFT/KICK STARTER • C L U T C H F R I C T I O N D I S C SERVICE L I M I T : 2.6 mm (0.1024 in.) I N S P E C T I O N Check the f r i c t i o n discs, replacing those which are discolored or worn.
  • Page 93 CLUTCH/OIL PUMP/GEAR SHIFT/KICK STARTER • CLUTCH OUTER INSPECTION Check the slots in the clutch outer for nicks, cuts or indentations made by the f r i c t i o n discs. • CLUTCH REASSEMBLY Install the drive gear and the clutch outer. Install the splined washer.
  • Page 94 CM 1 8 5 T CLUTCH/OIL PUMP/GEAR SHIFT/KICK STARTER Install the 20 mm circlip. Install the springs and lifter plate and tighten the bolts. NOTE Tighten the bolts in two or more steps and in cross pattern. Install the clutch drive gear and oil pump drive gear.
  • Page 95 CLUTCH/OIL PUMP/GEAR SHIFT/KICK STARTER OIL PUMP NOTE Clean the oil filter screen at time of disassembly. Date of Issue: December, 1977 © HONDA MOTOR CO., L T D .
  • Page 96 CLUTCH/OIL PUMP/GEAR SHIFT/KICK STARTER • O I L PUMP REMOVAL Remove the generator cover and rotate the A.C. generator rotor counterclockwise until the cut- out of the oil pump gear aligns w i t h the mounting screws. Remove the three screws, and remove the oil pump.
  • Page 97 CLUTCH/OIL PUMP/GEAR SHIFT/KICK STARTER Measure the rotor-to-body clearance. SERVICE LIMIT: 0.25 mm (0.0098 in.) Measure the rotor-to-cover clearance. SERVICE L I M I T : 0.12 mm (0.0048 in. Remove the rotors. Remove the gear cover and the pump gear and pull the rotor shaft out.
  • Page 98 O I L P U M P I N S T A L L A T I O N Install the new O-ring correctly and instal the oil pump. Date of Issue: December 1977 8-11 © HONDA MOTOR CO.. L T D .
  • Page 99 CLUTCH/OIL PUMP/GEAR SHIFT/KICK STARTER GEAR SHIFT LINKAGE • DISASSEMBLY Remove the clutch. STOPPER A R M SPRING Remove the gear shift pedal and the stopper arm. Remove the stopper plate and the shift d i u m pins. D R U M STOPPER Remove the gear shift spindle.
  • Page 100 CM 1 8 5 T CLUTCH/OIL PUMP/GEAR SHIFT/KICK STARTER • ASSEMBLY Install the gear shift spindle. NOTE Insert the end of the return spring around the return spring pin. Install the stopper arm. NOTE Install the spring as shown. After installing, check stopper arm oper- ation.
  • Page 101 CLUTCH/OIL PUMP/GEAR SHIFT/KICK STARTER KICK STARTER Pull the kick starter spring out and remove the kick starter. RATCHET SPRING SPRING GUIDE PLATE 1 8 m m C I R C L I P STARTER SPINDLE Disassemble the spring, the spring guide and the pinion gear.
  • Page 102 CLUTCH/OIL PUMP/GEAR SHIFT/KICK STARTER Measure the kick starter pinion O.D. w i t h a micrometer. SERVICE L I M I T : 17.93 mm (0.7059 in.) • K I C K S T A R T E R A S S E M B L Y A L I G N PUNCH M A R K S RETURN SPRING Assemble the ratchet and the spring onto the...
  • Page 103 Install the kick starter pedal and right muffler. Refill the engine w i t h the recommended oil and check for level. (See page 2-2.) Start the engine and check clutch operation. Date of Issue: December, 1977 8-16 © HONDA MOTOR CO., LTD...
  • Page 104 CLUTCH/OIL PUMP/GEAR SHIFT/KICK STARTER TORQUE: 4 . 5 - 6 . 0 kg-m ( 3 2 . 5 - 4 3 . 4 ft-lb.) Date of Issue: December, 1977 © HONDA MOTOR CO., L T D .
  • Page 105 A.C.GENERATOR/ STARTER MOTOR SERVICE INFORMATION 9- -1 TROUBLESHOOTING 9 - 2 CONTACT BREAKER DISASSEMBLY 9 - 3 DRIVE SPROCKET REMOVAL 9 - 4 LEFT CRANKCASE COVER REMOVAL 9- -6 A.C. GENERATOR ROTOR REMOVAL 9- -9 STARTING MOTOR REMOVAL 9 - 1 0 9- -10 STARTING MOTOR INSTALLATION 9- -11...

  • Page 106: Troubleshooting

    1. Faulty starter clutch 2. Faulty starter motor planetary gear 3. Drive chain or sprocket broken Starter Motor A n d Engine Turn But Engine Does Not Start 1. Ignition circuit problems Date of Issue: December, 1977 © HONDA MOTOR CO., LTD.

  • Page 107: Contact Breaker Disassembly

    A.C. GENERATOR/STARTER MOTOR CONTACT BREAKER DISASSEMBLY Remove the A.C. generator cover and gasket. Remove the base plate attaching screws. Disconnect the breaker point wire. Remove the breaker point attaching screws. Remove the oil felt attaching screw. CONTACT POINT O I L FELT BASE P L A T E •...

  • Page 108: Drive Sprocket Removal

    A.C. GENERATOR/STARTER MOTOR • C O N T A C T B R E A K E R P O I N T A S S E M B L Y The assembly sequence is essentially the reverse of disassembly. NOTE Moisten the felt w i t h a small amount of oil.

  • Page 109: Left Crankcase Cover Removal

    A.C. GENERATOR/STARTER MOTOR LEFT CRANKCASE COVER REMOVAL Remove the left muffler. Remove the gear shift pedal and remove the left crankcase rear cover. Remove the point cover. Disconnect the A.C. generator coupler Remove the left crankcase cover. Remove the stator coil. •...

  • Page 110: Generator Rotor Removal

    Block the clutch to prevent it f r o m turning w i t h a clutch outer holder and remove the rotor bolt. Remove the spark advancer. Date of Issue: December, 1977 © HONDA MOTOR CO.. L T D .
  • Page 111 ROTOR PLATE SPRING STARTING ROLLER CLUTCH OUTER Date of Issue: December, 1977 © H O N D A MOTOR CO., L T D .
  • Page 112 Remove the starter clutch outer and side plate. SHOCK D R I V E R Check the starter clutch outer for wear. WFAR Date of Issue: December, 1977 © HONDA MOTOR CO., LTD...

  • Page 113: Starting Motor Removal

    A.C. GENERATOR/STARTER MOTOR • S T A R T E R C L U T C H R E A S S E M B L Y Install the dowel pin and side plate. DOWEL PIN NOTE Align the dowel pin w i t h the side plate STARTER C L U T C H OUTER pin holes.

  • Page 114: Starting Motor Installation

    Install the left side spacer. NOTE • Install the knock pins and gasket at the time of assembly. • For cable routing, refer to page 1-11. Date of Issue: December, 1977 9 - 1 0 © HONDA MOTOR CO., L T D .

  • Page 115: A.c. Generator Installation

    A.C. GENERATOR/STARTER MOTOR Install the starter motor. NOTE Install the O-ring at the time of assembly. Install the starter chain, starter sprocket and CRANKCASE starter motor sprocket at the same time. Install the sprocket setting plate. NOTE • Note the direction of sprockets. •...

  • Page 116: Left Crankcase Cover Installation

    A.C. GENERATOR/STARTER MOTOR Install the spark advancer. NOTE Align the knock pin on the spark ad- vancer w i t h the groove of rotor. Tighten the rotor bolt. T O R Q U E : 4 . 5 - 5 . 0 kg-m ( 3 2 . 5 - 3 6 . 2 ft-lb.) When tightening the bolt, hold the clutch lifter plate w i t h a clutch holder.
  • Page 117 A.C. GENERATOR/STARTER MOTOR TORQUE: 4.5—5.0 kg-m ( 3 2 . 5 - 3 6 . 2 ft-lb.)
  • Page 118 TRANSMISSION/ 1 0 . CRANKSHAFT SERVICE INFORMATION 1 0 - 1 TROUBLESHOOTING 1 0 - 2 CRANKCASE DISASSEMBLY 1 0 - 3 TRANSMISSION REMOVAL 1 0 - 4 TRANSMISSION DISASSEMBLY 1 0 - 5 CRANKSHAFT REMOVAL 1 0 - 6 BALL BEARING INSTALLATION 1 0 - 8 CRANKSHAFT INSTALLATION...
  • Page 119 TRANSMISSION/CRANKSHAFT • SERVICE DATA ITEMS S T A N D A R D SERVICE L I M I T Shift fork I.D. 12.000-12.018 mm (0.4724-0.4731 in.) 12.05 mm (0.4744 in.) End thickness 5 . 0 0 - 5 . 0 7 mm ( 0 . 1 9 6 9 - 0 . 1 9 9 6 in.) 4.70 mm (0.1850 in.) Shift fork guide shaft O.D.
  • Page 120 HONDA. C M 1 8 5 T TRANSMISSION/CRANKSHAFT CRANKCASE DISASSEMBLY Place the engine w i t h the left crankcase up- wards and remove the 6 mm screws. Place the engine w i t h the right crankcase uo- wardsand remove the setting bolts.
  • Page 121 WEAR OR D A M A G E Check each shift fork end thickness. END THICKNESS SERVICE L I M I T : 4.70 mm (0.1850 in.) Date of Issue: December, 1977 10-4 © HONDA MOTOR CO., L T D .
  • Page 122 TRANSMISSION/CRANKSHAFT Measure the shift f o r k guide shaft O.D. in two directions at right angle to each other. SERVICE L I M I T : 11.96 mm (0.4709 in.) Check the gearshift drum for wear or dam- age. TRANSMISSION DISASSEMBLY Disassemble the transmission gears and inspect each gear for wear...
  • Page 123 TRANSMISSION/CRANKSHAFT CRANKSHAFT REMOVAL Remove the crankshaft after unscrewing the five setting bolts and nut. Pry off the lock pin and remove the plain washer. Remove the tensioner arm. Set the crank weight balancer to the position shown and remove the cam chain. 10-6 Date of Issue: December, 1977 ©...
  • Page 124 TRANSMISSION/CRANKSHAFT • C R A N K S H A F T I N S P E C T I O N SERVICE LIMIT: Measure the connecting rod big end side 0.6 mm 10.0236 in.) clearance. Measure the radial clearance at two different SERVICE L I M I T : points across f r o m each other as shown.
  • Page 125 L E F T C R A N K C A S E Install the ball bearing w i t h a bearing driver. 1 0 - 8 Date of Issue: December, 1977 © HONDA MOTOR CO., L T D .
  • Page 126 TRANSMISSION/CRANKSHAFT Install the oil seal. CA UTION drive Do not the countershaft oil seal below the end of the crankcase as tha, will block up the oil passage in the shaft. Install the O-ring and the oil through plate, Tighten the screws. NOTE Apply locking agent to the screws.
  • Page 127 Tighten the nut and five bolts. TORQUE. 1.0—1.4 kg-m ( 7 . 2 - 1 0 . 1 ft-lb.) Date of Issue: December, 1977 1 0 - 1 0 © HONDA MOTOR CO.. L T D .
  • Page 128 TRANSMISSION/CRANKSHAFT TRANSMISSION ASSEMBLY NOTE After assembly, apply oil to each gear and shaft. COUNTERSHAFT LOW GEAR 3RD GEAR 4TH GEAR 2ND GEAR LOW GEAR M A I N S H A F T SIDE C O L L A R Assemble the mainshaft and the countershaft shown above.
  • Page 129 TRANSMISSION/CRANKSHAFT Install the shift drum into the left crankcase. NOTE Align the neutral switch rotor w i t h the neutral switch on the left crankcase. N E U T R A L SWITCH ROTOR N E U T R A L SWITCH Insert the shift forks in the grooves of the shift d r u m , NOTE...
  • Page 130 T R A N S M I S S I O N / C R A N K S H A F T CRANKCASE ASSEMBLY Insert the dowel pins and install the gasket correctly. Install the right crankcase on the left crank- case.
  • Page 131 1 . 0 - 1 . 4 kg-m ( 7 . 2 - 1 0 . 1 ft-lb.) T O R Q U E : 1.0-1.4 kg-m ( 7 . 2 - 1 0 . 1 ft-lb.) Date of Issue: December, 1977 © HONDA MOTOR CO., LTD.
  • Page 132 Tool No. 0 7 7 4 7 - 0 0 1 0 1 0 0 Driver attachment Tool No. 0 7 7 4 7 - 0 0 1 0 4 0 0 Date of Issue: December, 1977 11 -1 © HONDA MOTOR CO., L T D .
  • Page 133 STEERING/FRONT WHEEL/FRONT SUSPENSION • TORQUE Steering stem nut' 6 . 0 - 7 . 0 kg-m ( 4 3 . 4 - 5 0 . 6 ft-lb.) Handlebar upper holder bolt: 2 . 0 - 2 . 5 kg-m ( 1 4 . 5 - 1 8 . 1 ft-lb.) Fork t o p bridge b o l t : 2 .

  • Page 134: Troubleshooting

    STEERING/FRONT WHEEL/FRONT SUSPENSION TROUBLESHOOTING Wobble or Vibration in Motorcycle 1. Loose axle 2. Loose wheel bearings 3. Loose steering stem nut or bearings 4. Unbalanced tire and wheel 5. Loose spokes 6. Bent wheel 7. Excessive lateral runout in wheel 8.

  • Page 135: Headlight

    STEERING/FRONT WHEEL/FRONT SUSPENSION HEADLIGHT • H E A D L I G H T C A S E R E M O V A L Remove the headlight and disconnect each coupler and connector NOTE Do not cut the wires. Remove the headlight case f r o m headlight...

  • Page 136: Speedometer

    STEERING/FRONT WHEEL/FRONT SUSPENSION SPEEDOMETER • S P E E D O M E T E R R E M O V A L Unscrew the cap nut under the speedometer. Remove the cable f r o m the speedometer. Remove headlight and disconnect the speedometer wire.

  • Page 137: Handlebar

    STEERING/FRONT WHEEL/FRONT SUSPENSION HANDLEBAR STARTER A N D ENGINE TURN S I G N A L HORN • HANDLEBAR REMOVAL STOP SWITCH A N D DIMMER SWITCH Loosen the t w o screws at the starter switch and remove the wire band. Remove the throttle grip and switch w i t h the f r o n t brake cable and t h r o t t l e cable.
  • Page 138 STEERING/FRONT WHEEL/FRONT SUSPENSION • HANDLEBAR INSTALLATION TORQUE: 2 . 0 - 2 . 5 kg-m Place the handlebar on the lower holder. 114.5-18.9 ft-lb.) NOTE Align the punch marks on the handlebar with the top face of the lower holder. Install the upper holder.

  • Page 139: Front Wheel

    Set the axle in V b l o c k s , rotate and measure the runout. SERVICE LIMIT: Actual runout is 1/2 of Total Indicator Reading 0.2 mm (0.0079 in.) (TIR). Date of Issue: December, 1977 11-8 © HONDA MOTOR CO., L T D .
  • Page 140 C M 1 8 5 T STEERING/FRONT WHEEL/FRONT SUSPENSION • FRONT WHEEL BEARING PLAY INSPECTION Check wheel bearings by placing the wheel on a trueing stand and spinning the wheel by hand. Replace the bearings if they are noisy PLAY or have excessive play.
  • Page 141 Grease the inside of the dust seal. Install the dust seal and the collar on right side of f r o n t wheel hub. Date of Issue: December, 1977 1 1 - 1 0 © HONDA MOTOR CO., LTD.
  • Page 142 Check the brake lever free play and inspect the speedometer operation. Date of Issue: December, 1977 11-11 © HONDA MOTOR CO , L T D .

  • Page 143: Front Brake Panel

    STEERING/FRONT WHEEL/FRONT SUSPENSION FRONT BRAKE PANEL B R A K E SHOE NOTE A p p l y grease to the speedometer gear FRONT B R A K E PANEL when assembling. RETURN SPRING BRAKE CAM INDICATOR PLATE BRAKE A R M •...
  • Page 144 STEERING/FRONT WHEEL/FRONT SUSPENSION Grease the sliding surface of the brake cam and install. Install the return springs on the brake shoes. Install the washer. Insert the cotter pin and spread the ends as shown. WARNING A void getting grease on the brake lining. COTTER PIN WASHER Install the dust seal and the indicator pla.te...

  • Page 145: Front Fork

    Loosen the bolts on the fork t o p and bottom bridges. NOTE Slightly loosening the fork bolt while it is installed in the stem makes disassembly easier. Pull down while turning the fork tube Date of Issue: December, 1977 1 1 - 1 4 © HONDA MOTOR CO., LTD.
  • Page 146 C M l 85T STEERING/FRONT WHEEL/FRONT SUSPENSION • F R O N T F O R K D I S A S S E M B L Y Remove the f o r k bolt. Remove the fork spring. FORK SPRING FORK BOLT »...
  • Page 147 Divide total indicator reading by 2 to deter- mine actual runout. SERVICE L I M I T : 0.2 mm (0.0079 in.) Date of Issue: December, 1977 11-16 © HONDA MOTOR CO.. L T D .
  • Page 148 STEERING/FRONT WHEEL/FRONT SUSPENSION Measure at several points along the sliding O.D. SERVICE L I M I T : 30.87 mm (1.2154 in. surface (260 mm f r o m b o t t o m to top) Remove the dust seal and pry off the set ring w i t h the snap ring pliers.
  • Page 149 FORK BOLT OIL LOCK PIECE FORK TUBE SET RING O I L SEAL FORK SLIDER SOCKET BOLT Date of Issue: December, 1977 1 1 - 1 8 © HONDA MOTOR CO.. L T D .
  • Page 150 CM 1 8 5 T STEERING/FRONT WHEEL/FRONT SUSPENSION Insert the seat pipe into the f o r k tube and set the oil lock piece on the end of seat pipe. A L L E N WRENCH Insert the parts into the fork slider and tighten NO.
  • Page 151 TORQUE: 2 . 0 - 2 . 5 kg-m ( 1 4 . 5 - 1 8 . 1 ft-lb.) Install the f r o n t fender and the front wheel. Date of Issue: December, 1977 1 1 - 2 0 © HONDA MOTOR CO., L T D .

  • Page 152: Steering Stem

    C M 1 8 5 T STEERING/FRONT WHEEL/FRONT SUSPENSION STEERING STEM • TOP BRIDGE REMOVAL Remove the steering handlebar. (See page 11-6.) Remove the headlight and headlight case. Remove the headlight bracket. Remove the stem nut. Loosen the fork t o p bridge bolts and remove the t o p bridge.
  • Page 153 C M 1 8 5 T STEERING/FRONT WHEEL/FRONT SUSPENSION • STEERING STEM REMOVAL Remove the f r o n t fork. PIN SPANNER Remove the head t o p thread. NOTE Support the stem to prevent it f r o m falling and remove the upper cone race and ball bearings.
  • Page 154 STEERING/FRONT WHEEL/FRONT SUSPENSION • S T E E R I N G S T E M A S S E M B L Y Install the steel balls, the cone races, the dust seal and the steering stem. PIN SPANNER NOTE Grease the steel balls and the ball race.
  • Page 155 STEERING/FRONT WHEEL/FRONT SUSPENSIÓN TORQUE: 2 . 0 - 2 . 5 kg-m ( 1 4 . 5 - 1 8 . 1 ft-lb.) TORQUE: 6 . 0 - 7 . 0 kg-m ( 4 3 . 4 - 5 0 . 6 ft-lb.) T O R Q U E : T O R Q U E : 2 .

  • Page 156: Service Information

    Swingarm pivot bushing clearance 0 . 2 - 0 . 3 mm ( 0 . 0 0 7 9 - 0 . 0 1 1 8 in.) Date of Issue: December, 1977 12-1 © HONDA MOTOR CO., L T D .
  • Page 157 REAR WHEEL/REAR SUSPENSION TROUBLESHOOTING Rattle In Rear Wheel 1. Bent rear wheel 2. Worn rear wheel bearing 3. Loose spokes 4. Faulty tire 5. Loose axle nut 6. Loose rear fork bolt 7. Swingarm bushing worn Soft Rear Suspension 1. Broken rear spring(s) 2.
  • Page 158 I N S P E C T I O N Turn the rear wheel by hand to check for condition. Replace the bearing if it is noisy or has excessive play PLAY Date of Issue: December. 1977 12-3 © HONDA MOTOR CO., L T D .
  • Page 159 C M 1 8 5 T REAR WHEEL/REAR SUSPENSION • REAR WHEEL RUNOUT SERVICE LIMITS: Measure the rear wheel runout. RADIAL: 2.0 mm (0.0787 in. A X I A L : 2.0 mm (0.0787 in. • REAR WHEEL DISASSEMBLY WHEEL NOTE If the bearings are removed they should be replaced w i t h new ones.
  • Page 160 REAR WHEEL/REAR SUSPENSION • REAR SPROCKET DISASSEMBLY DAMPER BUSHING DRIVEN SPROCKET F I X I N G BOLT SNAP RING • FINAL DRIVEN SPROCKET WEAR Inspect the drive chain and the sprocket before installing. Replace the drive chain and sprocket if they show excessive wear or damage.
  • Page 161 REAR WHEEL/REAR SUSPENSION \ S / C M 1 8 5 T • REAR SPROCKET ASSEMBLY Install the fixing bolts. NOTE Be sure the fixing bolts are seated in the sprocket groove properly. F I X I N G BOLT Grease the left side of rear wheel hub and inside of the driven sprocket.
  • Page 162 REAR WHEEL/REAR SUSPENSION • BRAKE DRUM I.D. I.D. SERVICE L I M I T : 131.0 mm (5.1575 in.) Measure I.D. of the brake drum. • REAR WHEEL INSTALLATION Install the rear wheel and the axle shaft. R O T A T I N G DIRECTION Install the drive chain on the drive and driven sprockets.
  • Page 163 Remove the brake shoe springs. Replace the brake shoes. C O T T E R PIN B R A K E S H O E S Date of Issue: December, 1977 12-8 © HONDA MOTOR CO., L T D .
  • Page 164 REAR WHEEL/REAR SUSPENSION A p p l y grease on the sliding face of the brake cam and install it. Install the brake shoe return springs on to the brake shoes. Install the washer and cotter pin. WASHER NOTE Install and spread the ends of the cotter pin as shown.
  • Page 165 N O . 0 7 9 5 9 - 3 2 9 0 0 0 1 UPPER H O L D E R L O C K N U T R E A R D A M P E R Date of Issue: December, 1977 12-10 © HONDA MOTOR CO., L T D .
  • Page 166 R E A R W H E E L / R E A R S U S P E N S I O N • S H O C K A B S O R B E R S P R I N G F R E E L E N G T H Measure the spring free length.
  • Page 167 I N S P E C T I O N 0.5 mm (0.0197 in. Measure the O.D. of collars and I.D. of bushing and inspect the pivot-to-bushing clearance. Date of Issue: December, 1977 12-12 © HONDA MOTOR CO., L T D .
  • Page 168 NOTE Note the location of the stoplight switch spring. After installing the brake pedal, adjust the free play. (See page 3-13.) Date of Issue: December, 1977 1 2 - 1 3 © HONDA MOTOR CO., L T D .
  • Page 169 REAR WHEEL/REAR SUSPENSION Date of Issue: December, 1977 © H O N D A MOTOR CO.. L T D .
  • Page 170 FUELTANK/AIR CLEANER/ REAR FENDER CRANKCASE BREATHER FUEL TANK FILTER SCREEN Clean the filter w i t h compressed air. Gasoline is flammable. Keep sparks and flame away during fuel valve assembly. Remove the seat. GASKET Turn the fuel valve " O F F " and disconnect the After installing, check fuel tube.
  • Page 171 FUEL TANK/AIR CLEANER/ REAR FENDER/CRANKCASE BREATHER REAR FENDER • REAR FENDER REMOVAL Remove the seat Remove the rear fender. Separate the rear fender A and fender B. • R E A R F E N D E R I N S T A L L A T I O N NOTE Install fender B into the groove of fender Date of Issue: December, 1977...
  • Page 172 FUEL TANK/AIR CLEANER/ REAR FENDER/CRANKCASE BREATHER CRANKCASE BREATHER Rout the breather tubes as shown. Date of Issue: December, 1977 1 3 - 3 © H O N D A MOTOR CO.. L T D .
  • Page 173 BATTERY/ CHARGING SYSTEM SERVICE INFORMATION 1 4 - 1 TROUBLESHOOTING 1 4 - 2 BATTERY 1 4 - 3 CHARGING SYSTEM 1 4 - 4 SERVICE INFORMATION • W O R K I N G P R A C T I C E This section describes the electric parts service.
  • Page 174 BATTERY/CHARGING SYSTEM TROUBLESHOOTING No Power - Key Turned On 1. Dead battery a. Battery electrolyte evaporated b. Ignition switch left on c. Charging system failure 2. Disconnected battery cable 3. Main fuse burned out 4. Faulty ignition switch Low Power — Key Turned On 1.
  • Page 175 BATTERY/CHARGING SYSTEM BATTERY • BATTERY REMOVAL Disconnect the negative cable. Remove the strap. Disconnect the positive cable. Remove the battery case w i t h in battery. • TESTING SPECIFIC GRAVITY The specific gravity of the battery must be checked w i t h a hydrometer. F U L L Y CHARGED: 1 .
  • Page 176 CHARGING S T A R T I N G SPEED: 2,200 rpm 3.3 Amp Min. at 5,000 rpm at 7.0V (of battery) 6.0 Amp Max. at 10,000 rpm at 8.3V (of battery) Date of Issue: December, 1977 14-4 © HONDA MOTOR CO., L T D .
  • Page 177 G R E E N GREEN COLOR COLOR COLOR COLOR COLOR PINK GREEN Y E L L O W GREEN Y E L L O W RED/WHITE Date of Issue: December, 1977 14-5 © HONDA MOTOR CO.. L T D .
  • Page 178 A.C. GENERATOR "=" H E A D L I G H T INSTRUMENT GREEN LIGHT Y E L L O W WHITE PINK B r - BROWN BLUE Date of Issue: December, 1977 © HONDA MOTOR CO.. L T D .
  • Page 179 15. IGNITION SYSTEM SERVICE INFORMATION 15- -1 TROUBLESHOOTING 15- -2 IGNITION COIL 15- -3 CONDENSER 15- -4 SERVICE INFORMATION • WORKING PRACTICE This section describes the parts of the ignition system. Spark plug: Refer to section 3. Contact breaker; Refer to section 9. Be sure that the battery is fully charged before diagnosing troubles in the ignition system.
  • Page 180 1. Improper ignition timing Misfiring during Acceleration 1. Worn spark plug, breaker points and/or ignition wires 2. Incorrect ignition timing Backfiring 1. Ignition timing incorrect 2. Ignition malfunction Date of Issue: December, 1977 15-2 © HONDA MOTOR CO.. L T D .
  • Page 181 3-point spark test. The coil is satisfactory if the spark jumps across the gap greater than 6 mm (0.24 in.). SPARK DISTANCE AT LEAST 6 mm (0.24 in.) Date of Issue: December, 1977 15-3 © HONDA MOTOR CO., L T D .
  • Page 182 Disconnect the condenser wire f r o m the con- nector. Remove the condenser. Condenser may be located under the gas tank on right side of bike. Date of Issue: December, 1977 1 5 - 4 © HONDA MOTOR CO., LTD.
  • Page 183 Measure the capacity after shorting the con- denser. S H O R T I N G T H E CONDENSER Measure the condenser capacity. BLUE WIRE Date of Issue: December, 1977 15-5 © HONDA MOTOR CO., L T D .
  • Page 184 B A T T E R Y S P A R K P L U G S CONDENSER CONTACT B R E A K E R WHITE B K - BLACK BLUE Date of Issue: December, 1977 © HONDA MOTOR CO., L T D .
  • Page 185 ELECTRIC STARTER 1 6 . SYSTEM SERVICE INFORMATION 1 6 - 1 TROUBLESHOOTING 1 6 - 2 STARTING MOTOR 1 6 - 3 STARTER MAGNETIC SWITCH 1 6 - 6 SERVICE INFORMATION • WORKING PRACTICE This section describes servicing of the starter motor. Starter motor removal: Refer to section 9.
  • Page 186 ELECTRIC STARTER SYSTEM TROUBLESHOOTING Starter Motor Will Not Turn 1. Dead battery 2. Faulty ignition switch 3. Faulty start switch 4. Faulty neutral switch 5. Faulty starter relay 6. Loose or disconnected wire or cable 7. Neutral diode open Starter Motor Turns Engine Slowly 1.
  • Page 187 ELECTRIC STARTER SYSTEM STARTING MOTOR O-RING FIELD COIL A R M A T U R E COIL O-RING CARBON BRUSH THRUST WASHER BRUSH HOLDER PLATE REAR COVER • C A R B O N B R U S H R E M O V A L Remove the starter motor case screws and the rear cover.
  • Page 188 C O I L I N S U L A T I O N T E S T There may be no continuity between com- mutators and the shaft. Date of Issue: December, 1977 16-4 © HONDA MOTOR CO., L T D .
  • Page 189 ELECTRIC STARTER SYSTEM • F I E L D C O I L I N S P E C T I O N Check for continuity from the cable terminal to the motor case and f r o m the cable terminal to the brush wire.
  • Page 190 ELECTRIC STARTER SYSTEM STARTER MAGNETIC SWITCH • I N S P E C T I O N Check for continuity f r o m Yellow/Red wire to Black wire. Yellow/Red wire to Black wire: Continuity BLACK • S W I T C H O P E R A T I O N T E S T Connect...
  • Page 191 ELECTRIC STARTER SYSTEM STARTER MOTOR I G N I T I O N STARTER MOTOR BK— BLACK Y— Y E L L O W Date of Issue: December, 1977 © HONDA MOTOR CO., LTD.
  • Page 192 Tail/stoplight: 3/32 cp Turn signal light: 21 cp Meter lights: 2 cp Neutral indicator. 2 cp Turn signal indicator: 1 cp High beam indicator: 1 cp Date of Issue: December, 1977 17-1 © HONDA MOTOR CO.. L T D .

  • Page 193: Troubleshooting 17- -2

    Headlight Beams Do Not Shift When HI-LO Switch Is Operated 1. Beam filament burned out 2. Faulty dimmer switch 3. Faulty starter b u t t o n in free position Date of Issue: December, 1977 17-2 © HONDA MOTOR CO., LTD.

  • Page 194: Ignition Switch

    SWITCHES/LIGHTS/HORN IGNITION SWITCH Remove the headlight and disconnect the headlight switch coupler {white coupler). There should be continuity as indicated by 0 - 0 in the BROWN BROWN/WHITE table. TURN SIGNAL SWITCH Disconnect the winker switch coupler (red coupler). There should be continuity as indicated by 0 - 0 in the table.

  • Page 195: Horn Switch

    Disconnect the dimmer switch coupler (red coupler) and wire connectors (blue/white wire and white wire). There should be continuity as indicated by 0 - 0 in the table. Date of Issue: December, 1977 17-4 © HONDA MOTOR CO., L T D .

  • Page 196: Starter Switch

    H O N D A . CM 1 8 5 T SWITCHES/LIGHTS/HORN STARTER SWITCH Disconnect the black coupler. There should be continuity as indicated by 0—0 in the table. ENGINE STOP SWITCH Disconnect the engine stop switch coupler (black coupler). B L A C K B L A C K / W H I T E Y E L L O W / R E D...

  • Page 197: Front Stop Light Switch

    There should be continuity w i t h the brake lever is pulled. HORN Test the horn sound by applying 6 volt battery directly. If sound is small, adjust the horn sound by turning the adjusting screw. 17-6 Date of Issue: December, 1977 © HONDA MOTOR CO., L T D .
  • Page 198 SWITCHES/LIGHTS/HORN Date of Issue: December, 1977 © H O N D A MOTOR CO., L T D .
  • Page 199 TROUBLESHOOTING 1 8 . CHART ENGINE WILL NOT START OR HARD TO START 1 8 - 2 ENGINE LACKS POWER 1 8 - 3 POOR PERFORMANCE AT IDLE AND LOW SPEED 1 8 - 4 POOR HIGH SPEED PERFORMANCE 1 8 - 5 SMOKING EXHAUST 1 8 - 5 FAULTY CLUTCH...
  • Page 200 TROUBLESHOOTING CHART ENGINE WILL NOT START OR IS HARD TO START Possible Cause: 1 . Check i f fuel reaches F U E L DOES NOT REACH • I D Empty fuel tank carburetor CARBURETOR (2) Clogged fuel line between fuel tank & carburetor (3) Clogged fuel valve F U E L REACHES...
  • Page 201 TROUBLESHOOTING CHART ENGINE LACKS POWER Possible Cause: (1) Dragging brake 1. Raise wheels off ground & WHEELS DO NOT SPIN spin F R E E L Y Faulty wheel bearing (3) Overtightened drive chain WHEELS SPIN F R E E L Y INCORRECT T I R E PRESSURE (1 ) Punctured tire 2.
  • Page 202 WEAK OR I N T E R M I T T E N T (2) Fouled, rough, or pitted breaker SPARK test spark point surface (3) Condenser shorted GOOD SPARK Date of Issue: December, 1977 18-4 © HONDA MOTOR CO., L T D .
  • Page 203 TROUBLESHOOTING CHART POOR HIGH SPEED PERFORMANCE Possible Cause: 1. Check ignition timing & INCORRECT T I M I N G & ^ ( 1 ) Incorrect timing adjustment valve clearance C L E A R A N C E Incorrect valve clearance CORRECT T I M I N G &...
  • Page 204 (2) Shift spindle interferring w i t h case or cover GEARS JUMPING OUT OF (1) Bent shifting gear or w o r n shift fork (2) Broken or weakened shift drum POSITION stopper spring Date of Issue: December, 1977 18-6 © HONDA MOTOR CO., L T D .
  • Page 205 TROUBLESHOOTING CHART ENGINE NOISE Possible Cause: TAPPET NOISE (1 ) Excessive valve clearance (2) Worn tappet PISTON SLAP (1 ) Worn piston & cylinder (2) Excessive carbon in combustion chamber (3) Worn piston pin & connecting rod small end CAM C H A I N NOISE (1) Worn camshaft bearing &...
  • Page 206 (4) Oil or grease on brake lining (5) Worn brake lining ELONGATED DRIVE CHAIN Possible Cause: (1) Incorrect adjustments (2) Not lubricated sufficiently enough (3) Worn sprocket Date of Issue: December, 1977 18-8 © HONDA MOTOR CO., L T D .

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