
TROUBLESHOOTING
8-1
EAS28451
TROUBLESHOOTING
EAS28460
GENERAL INFORMATION
TIP
The following guide for troubleshooting does
not cover all the possible causes of trouble. It
should be helpful, however, as a guide to basic
troubleshooting. Refer to the relative proce-
dure in this manual for checks, adjustments,
and replacement of parts.
EAS28470
STARTING FAILURES
Engine
1. Cylinder and cylinder head
• Loose spark plug
• Loose cylinder head or cylinder
• Damaged cylinder head gasket
• Damaged cylinder gasket
• Worn or damaged cylinder
• Incorrect valve clearance
• Improperly sealed valve
• Incorrect valve-to-valve-seat contact
• Incorrect valve timing
• Faulty valve spring
• Seized valve
2. Piston and piston ring
• Improperly installed piston ring
• Damaged, worn or fatigued piston ring
• Seized piston ring
• Seized or damaged piston
3. Air filter
• Improperly installed air filter
• Clogged air filter element
4. Crankcase and crankshaft
• Improperly assembled crankcase
• Seized crankshaft
Fuel system
1. Fuel tank
• Empty fuel tank
• Clogged fuel strainer
• Clogged fuel tank breather hose
• Deteriorated or contaminated fuel
2. Fuel cock
• Clogged or damaged fuel hose
3. Carburetor
• Deteriorated or contaminated fuel
• Clogged pilot jet
• Clogged pilot air passage
• Sucked-in air
• Damaged float
• Worn needle valve
• Improperly installed needle valve seat
• Incorrect fuel level
• Improperly installed pilot jet
• Clogged starter jet
• Faulty starter plunger
Electrical system
1. Battery
• Discharged battery
• Faulty battery
2. Fuse
• Blown, damaged or incorrect fuse
• Improperly installed fuse
3. Spark plug
• Incorrect spark plug gap
• Incorrect spark plug heat range
• Fouled spark plug
• Worn or damaged electrode
• Worn or damaged insulator
• Faulty spark plug cap
4. Ignition coil
• Cracked or broken ignition coil body
• Broken or shorted primary or secondary
coils
• Faulty spark plug lead
5. Ignition system
• Faulty CDI unit
• Faulty pickup coil
• Faulty stator coil
• Broken generator rotor woodruff key
6. Switches and wiring
• Faulty main switch
• Faulty engine stop switch
• Broken or shorted wiring
• Faulty neutral switch
• Faulty start switch
• Faulty clutch switch
• Improperly grounded circuit
• Loose connections
7. Starting system
• Faulty starter motor
• Faulty starter relay
• Faulty starting circuit cut-off relay
• Faulty starter clutch
EAS28490
INCORRECT ENGINE IDLING SPEED
Engine
1. Cylinder and cylinder head
• Incorrect valve clearance
• Damaged valve train components
Summary of Contents for RAPTOR YFM125RA
Page 1: ...SERVICE MANUAL YFM125RA 2011 2PA 28197 10 LIT 11616 24 36 ...
Page 6: ......
Page 8: ......
Page 42: ...TIGHTENING TORQUES 2 19 ...
Page 46: ...LUBRICATION SYSTEM CHART AND DIAGRAMS 2 23 EAS20410 LUBRICATION DIAGRAMS ...
Page 48: ...LUBRICATION SYSTEM CHART AND DIAGRAMS 2 25 ...
Page 50: ...CABLE ROUTING 2 27 EAS20430 CABLE ROUTING Handlebar top view ...
Page 52: ...CABLE ROUTING 2 29 Frame right side view ...
Page 54: ...CABLE ROUTING 2 31 Rear brake right side view ...
Page 56: ...CABLE ROUTING 2 33 Frame left side view ...
Page 58: ...CABLE ROUTING 2 35 Rear frame left side view ...
Page 60: ...CABLE ROUTING 2 37 Front fender top view ...
Page 62: ...CABLE ROUTING 2 39 Frame top view ...
Page 64: ...CABLE ROUTING 2 41 Air filter case top view ...
Page 66: ...CABLE ROUTING 2 43 ...
Page 68: ...REPLACING THE HEADLIGHT BULB 3 25 ADJUSTING THE HEADLIGHT BEAM 3 26 ...
Page 69: ......
Page 96: ...PERIODIC MAINTENANCE 3 27 ...
Page 115: ...REAR AXLE AND REAR AXLE HUB 4 16 ...
Page 144: ...HANDLEBAR 4 45 Throttle cable free play 2 0 4 0 mm 0 08 0 16 in ...
Page 163: ......
Page 207: ...OIL PUMP 5 44 ...
Page 246: ...CARBURETOR 6 11 ...
Page 248: ...IGNITION SYSTEM 7 1 EAS27090 IGNITION SYSTEM EAS27100 CIRCUIT DIAGRAM ...
Page 252: ...ELECTRIC STARTING SYSTEM 7 5 EAS27160 ELECTRIC STARTING SYSTEM EAS27170 CIRCUIT DIAGRAM ...
Page 258: ...CHARGING SYSTEM 7 11 EAS27200 CHARGING SYSTEM EAS27210 CIRCUIT DIAGRAM ...
Page 259: ...CHARGING SYSTEM 7 12 2 Stator coil 3 Rectifier regulator 5 Battery 8 Fuse ...
Page 261: ...CHARGING SYSTEM 7 14 ...
Page 262: ...LIGHTING SYSTEM 7 15 EAS27240 LIGHTING SYSTEM EAS27250 CIRCUIT DIAGRAM ...
Page 266: ...SIGNALING SYSTEM 7 19 EAS27270 SIGNALING SYSTEM EAS27280 CIRCUIT DIAGRAM ...
Page 270: ...CARBURETOR HEATING SYSTEM 7 23 EAS27490 CARBURETOR HEATING SYSTEM EAS27500 CIRCUIT DIAGRAM ...
Page 273: ...CARBURETOR HEATING SYSTEM 7 26 ...
Page 274: ...ELECTRICAL COMPONENTS 7 27 EAS27973 ELECTRICAL COMPONENTS ...
Page 276: ...ELECTRICAL COMPONENTS 7 29 EAS27981 CHECKING THE SWITCHES ...
Page 290: ...ELECTRICAL COMPONENTS 7 43 ...
Page 297: ......
Page 298: ...YAMAHA MOTOR CO LTD 2500 SHINGAI IWATA SHIZUOKA JAPAN ...
Page 299: ...WIRING DIAGRAM YFM125RA ...
Page 300: ...WIRING DIAGRAM YFM125RA ...