2003 Honda ATV TRX650FA Rincon Factory Service Manual, Page 150Get this manual
CYLINDER HEADIVAlVECAMSHAFT
TROUBLESHOOTING
Eng in to p-end problems usually affect engi ne performanceTh ese ca be di ag nose by co ressio esto by tracing to p-end no ise wi so un ing rod steth oscope If th performance is poor at low speeds, check fo hite smoke th crankcase reath er hoseIf he hose is smoky, check fo seized piston ri ng (page 9-2)
Com pression oo low, hard st art ing or po or performance at low spe ed
Valves:Incorrect va lve adjustmentBurned or bent va lve