2002 Bombardier Quest 650XT Service Manual, Page 114Get this manual
Subsection 08
Section 03 ENGINE (CYLINDER AND HEAD)
Ensure to seat valves properlyApply some lapping compound to valve face and work valve on its seat with lapping toolMeasure valve face contact widthNOTE: The location of contact area should be in center of valve seatMeasure valve seat width, using caliperVALVE SEAT CONTACT WIDTH mm (in) NEW Exhaust Intake 1.25 to 1.55 mm (.049 to .061 in) 1.10 to 1.30 mm (.043 to .051 in) SERVICE LIMIT Exhaust Intake mm (.078 in) 1.8 mm (.07 in)
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1Thrust washer 2Valve stem seal
If valve seat contact width is too wide or has dark spots, replace the cylinder head
Apply engine oil on valve stem and install itCAUTION: Be careful when valve stem is passed through sealing lips of valve stem seal2 1