2005-2008 Honda ATV TRX500FA/FGA Fourtrax, Rubicon Factory Service Manual, Page 174Get this manual
CYLINDER HEADVALVECAMSHAFT Subtract each valve stem O.Dfrom the corresponding guide I.Dto obtain the stem-to-guide clearanceSERVICE LIMITS: IN: 0.12 mm (0.005 in) EX: 0.14 mm (0.006 in)
Inspect and reface the valve seats whenever the valve guides are replaced (page 8-14)
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 replace the valve
VALVE GUIDE REPLACEMENT
Chill new valve guides in the freezer section of refrigerator for about an hourBe sure to wear heavy gloves to avoid burns when handling the heated cylinder headUsing torch to heat the cylinder head may cause warpage
VALVE GUIDE DRIVER