2006-2009 Honda TRX680 (TRX 680 FA-FGA) Factory Service Manual, Page 213Get this manual
CYLINDER HEADIVAlVECAMSHAFT
CYLINDER HEAD INSPECTION
CYLINDER HEAD
Be' carpfulno to diJmiJgc tho gasket
Remove the carbon deposits from the combustion cha mber, bei ng careful not to damage the gasket urface Chec the spark plug hole and valve areas for crac ks
COMBUSTION CHAMBER
Check the cyli nder head for warpage with straight edge and feeler gaugeS ERVICE LIMIT: 0.05 (OD02 in )