1999-2002 TRX400EX Fourtrax Service Manual, Page 255Get this manual
TROU BLESHOOTING
ENGINE LACKS POWER
Possi ble cause 1Raisewheel off the ground-Wheels does not spin freely and spin by hand Wheel spins freely Brake dragging Worn or damaged wheel bearings Drive chain too tight
2Checktire pressure- Pressure low Pressure normal
Faulty tire valve Puncturedtire
3Accelerate rapidly lowto Engine speed doesn't change
second Engine speed reduced when clutch is released
accordingly when clutch is released
Clutch slipping Worn clutch discsplates Warped clutch discsplates Weak clutch spring Additive in engine oil
4Accelerate lightly
Engine speed does not increase
ETne speed Inc,eases
Choke valve closed Clogged air cleaner Restrictedfuel flow Clogged muffler Restrictedfuel tank breathertube Faulty ignition control module