2005-2009 Honda TRX400EX/TRX400X Service Manual, Page 332Get this manual
TROUBLESHOOTING
ENGINE LACKS POWER
1Driv Train Inspection Raise wheels off the ground and spin by hand
Does the wheel spin freely?
NOBrake dragging Worn or damaged whee or axle bearing Drive chain too tightGO TO STEP 2
2Tire Pressure Inspection Check tire pressure
Are the tire pressures low?
YES NO Faulty tire valve Punct ured tireGO TO STEP 3
3Clut ch Inspection Accelerate rapidly from low to second
Does the engine speed change accordingly when clutch is engaged?
NOClutch slipping Worn clutch discs Warped clutch plates Weak clutch springs Damaged clutch lifter arm Additive in engine oi l
- GO TO STEP 5
4Engine Condition Inspection Accelerate lightly