Overcooling; Poor Braking Performance; Faulty Shock Absorber Assembly; Unstable Handling - Yamaha YFM70RY Service Manual

• Heavy carbon buildup
2. Engine oil
• Incorrect oil level
• Incorrect oil viscosity
• Inferior oil quality
Cooling system
1. Coolant
• Low coolant level
2. Radiator
• Damaged or leaking radiator
• Faulty radiator cap
• Bent or damaged radiator fin
3. Water pump
• Damaged or faulty water pump
4. Thermostat
• Thermostat stays closed
5. Fan motor
• Faulty fan motor
• Faulty coolant temperature sensor
6. Hose(s) and pipe(s)
• Damaged hose
• Improperly connected hose
• Damaged pipe
• Improperly connected pipe
Fuel system
1. Throttle body
• Damaged or loose throttle body joint
2. Air filter
• Clogged air filter element
Chassis
1. Brake(s)
• Dragging brake
Electrical system
1. Spark plug
• Incorrect spark plug gap
• Incorrect spark plug heat range
2. Ignition system
• Faulty ECU
EAS28610

OVERCOOLING

Cooling system
1. Thermostat
• Thermostat stays open
EAS28620

POOR BRAKING PERFORMANCE

• Worn brake pad
• Worn brake disc
• Air in hydraulic brake system
TROUBLESHOOTING
• Leaking brake fluid
• Faulty brake caliper kit
• Faulty brake caliper seal
• Loose union bolt
• Damaged brake hose
• Oil or grease on the brake disc
• Oil or grease on the brake pad
• Incorrect brake fluid level
EAS1S3L012

FAULTY SHOCK ABSORBER ASSEMBLY

Leaking oil
• Bent, damaged or rusty damper rod
• Cracked or damaged shock absorber
• Damaged oil seal lip
Malfunction
• Fatigue or damaged shock absorber spring
• Bent or damaged damper rod
EAS28670

UNSTABLE HANDLING

1. Handlebar
• Bent or improperly installed handlebar
2. Steering
• Incorrect toe-in
• Bent steering stem
• Improperly installed steering stem
• Damaged bearing or bearing race
• Bent tie-rods
• Deformed steering knuckles
3. Swingarm
• Worn bearing or bushing
• Bent or damaged swingarm
4. Shock absorber assembly
• Faulty shock absorber spring
• Leaking oil or gas
5. Tire(s)
• Uneven tire pressures (left and right)
• Incorrect tire pressure
• Uneven tire wear
6. Wheel(s)
• Incorrect wheel balance
• Deformed wheel
• Damaged or loose wheel bearing
• Bent or loose wheel axle
• Excessive wheel runout
7. Frame
• Bent frame
• Damaged frame
9-3