1995-2003 Honda Foreman TRX400FW TRX400 TRX 400 400FW Service Manual, Page 113Get this manual
CYLINDER HEAD CYLINDER PISTON
TROUBLESHOOTING
Engine 1Op-enj ptobiems ",ulily IffllCt engine performallCeTh_ prol)lem can be dilgnosed byf;Ompranion tKl Dr by tJa;ing engine noises.o the top-end with aDunding rod 5telhoKOpeb.uther lubeII the tube is smokyII th peform.nce II poor at low lpeedlch-:k lor whi Imoke in the check 10 seized pilton tlng
ExceMlve noise
VI'": Incorrect II,lve adjustmentBurned or bent v.I"- IncorllCt valtimingWalk valvelpring Cylrnoar IM!MI:leaking or dlmaged head ga5k81Warped or crllCled cylinder hud CylinoarpistonWorn cylinder or PIston .ing