1999-2002 TRX400EX Fourtrax Service Manual, Page 96Get this manual
CYLINDER HEAD VALVE VALVE STEMVALVE GUIDE Check that the valve moves smoothly in the guideCheck the valve for bending, burning or abnormal wearMeasure each valve stem 0.0and record itSERVICE LIMITS: IN: 5.46 mm (0.215 in) EX 5.44mm 10.214in)
Reamthe valve guide to remove any carbon build-up before measuring the guideInsert the reamer from the combustion chamber side of the head and always rotate the reamer clockwiseTOOL Valve guide reamer, 5.5 mm
079842000001 or 079842000000 (U.S.Aonly)
Measure each valve guide 1.0and record itSERVICE LIMIT 5.52 mm (0.217 in) Subtract each valve stem 0.0from the corresponding guide 1.0to obtain the stem-to-guide clearanceSERVICE LIMITS IN: 0.12 mm (0.005 in) EXO.14mm (0.006 in) If the stem-to-guide clearance exceeds the service limit, determine if new guide with standard dimensions would bring the clearance within toleranceIf so, replace any guides as necessary and ream to fitIf the stem-to-guide clearance exceeds the service limit with new guide, also replacethe valveNOTE: Inspect and reface the valve seats whenever the valve guides are replaced (page 7-13)