2002 Bombardier Quest 650XT Service Manual, Page 113Get this manual
Section 03 ENGINE Subsection 08 (CYLINDER AND HEAD)
Inspection
Valve Stem Seal Inspection of valve stem seals is not needed because new seals should always be installed whenever cylinder head is removedValve Inspect valve surface, check for abnormal stem wear and bendingIf so, replace by new oneValve Stem and Valve Guide Clearance Measure valve stem and valve guide in three places, using micrometer and small bore gaugeNOTE: Clean valve guide to remove carbon deposits before measuringChange valve if valve stem is out of specification or has other damages such as wear or friction surface
VALVE STEM DIAMETER mm (in) NEW MINIMUM Exhaust Intake 5.946 mm (.2341 in) 5.961 mm (.2347 in) NEW MAXIMUM Exhaust Intake 5.960 mm (.2346 in) 5.975 mm (.2352 in) SERVICE LIMIT Exhaust Intake 5.93 mm (.233 in)