Polaris 600 Dragon SP, Service Manual

Page: 72 / 308

ENGINE
3.22
VALVE INSPECTION
1. Remove all carbon from valves with a soft wire
wheel or brush.
2. Check valve face for runout, pitting, and burnt
spots. To check for bent valve stems, mount
valve in a drill or use “V” blocks and a dial
indicator.
3. Check end of valve stem for flaring, pitting, wear
or damage (A).
A
B
4. Inspect split keeper groove for wear or flaring of
the keeper seat area (B). NOTE: The valves can
be re-faced or end ground, if necessary. They
must be replaced if extensively worn, burnt, bent,
or damaged.
5. Measure diameter of valve stem with a
micrometer in three places, then rotate 90
degrees and measure again (six measurements
total). Compare to specifications.
Valve Stem Diameter:
Intake: 0.2356”
±
0.00039”
(5.985
±
0.01 mm)
Exhaust: 0.2346”
±
0.00039”
(5.96
±
0.01 mm)
Measure valve stem in several places.
Rotate the valve 90 degrees and mea-
sure for wear.
6. Measure valve guide inside diameter at the top
middle and end of the guide using a small hole
gauge and a micrometer. Measure in two
directions.
Valve Guide
Valve Guide I.D.:
0.2374”
±
0.00059” (6.030
±
0.015 mm)
7. Subtract valve stem measurement from the valve
guide measurement to obtain stem to guide
clearance. NOTE: The valve guides cannot be
replaced. Be sure to measure each guide and
valve combination individually.