2006-2009 Honda TRX680 (TRX 680 FA-FGA) Factory Service Manual, Page 211Get this manual
CYLINDER HEADIVAlVECAMSHAFT M easu re each follower bo re I.DSERVICE LIMIT: 22.54 mm (0.887 in)
Su bt ract each oll ower .0fro the corresponding bore I,Dto bta in the followe r-to-b ore clea ranceSERVICE LIM IT: 0.07 mm (0.003 jn )
CYLINDER HEAD REMOVAL
Remove the fo llowingther mostat (p age 7-8) throttle body (page 6-43) exhaust pipe (page 3-191 cylinder head cover page 9-6)