2006-2012 Honda TRX90 TRX90EX/X Service Manual, Page 108Get this manual
CYLINDER HEADVALVES Measu re and record each valve guide 1.0SERVICE LIMIT: IN EX:5.03 mm (0.198 in) Subtract each valve stem .0 from the corresponding guide 1.0to obtain the stem-to-guide clearanceSERVICE LIMITS: IN: 0.12 mm (0.005 in) EX: 0.14 mm (0.006 in) sears whenever the If the stem-to-guide clearance is out of specification, determine if new guide with standard imensions valve guides are would bring the clearance within toleranceIf so, replaced lpage 7- replace any guides as necessary and ream to fitIS}If the stem-to-guide clearance is out of specification ith the new guides, replace the valves and guidesReface the valve
VALVE GUIDE REPLACEMENT
Chill the replacement valve guides in the freezer section of refrige rator or about an hourDo nor use orch 10 hear che cylinder headIT may cause warpmg
Heat the cyl inder head to 100'50 (212302 F) with hot plate or ovenTo avoid burns, wear heavy gloves when handling the heated cylinder headSupport the cylinder head and drive out the valve guides from combustion chamber side of the cylinder head