2001-2005 Honda TRX250EX Sportrax TRX250EX Factory Service Manual, Page 301Get this manual
TROUBLESHOOTING From previous page
Possible cause
10Remove cylinder head cover and Valve train not lubricated
inspect lubrication Valve train lubricated properly properly
Clogged oil passage
Clogged oil orifice
or run at high speed Engine knocks
Engine does not knock
Worn piston and cylinder Use of poor quality fuel Excessive carbon build-up in combustion chamber Ignition timing advanced too far (Fau lty leM) Lean fuel mixture
POOR PERFORMANCE AT LOW AND IDLE SPEED
Possible cause
1Check carburetor pilot screw
Incorrect
See section 5