Polaris Sportsman 800 EFI 4x4 2012 Service Manual page 91

NOTE: Valve seat width and point of contact on the
valve face is very important for proper sealing. The
valve must contact the valve seat over the entire
circumference of the seat, and the seat must be the
proper width all the way around. If the seat is
uneven, compression leakage will result. If the seat
is too wide, seat pressure is reduced, causing
carbon accumulation and possible compression
loss. If the seat is too narrow, heat transfer from
valve to seat is reduced. The valve may overheat and
warp, resulting in burnt valves.
1. Install pilot into valve guide.
2. Apply cutting oil to valve seat and cutter.
3. Place 46° cutter on the pilot and make a light cut.
4. Inspect the cut area of the seat:
5. To check the contact area of the seat on the valve
6. Insert valve into guide and tap valve lightly into place
9924864 - 2012-2014 SPORTSMAN 800 / 6X6
© Copyright 2013 Polaris Sales Inc.
* If the contact area is less than 75% of the
circumference of the seat, rotate the pilot 180° and
make another light cut.
* If the cutter now contacts the uncut portion of the
seat, check the pilot. Look for burrs, nicks, or runout.
If the pilot is bent it must be replaced.
* If the contact area of the cutter is in the same place,
the valve guide is distorted from improper installation
* If the contact area of the initial cut is greater than
75%, continue to cut the seat until all pits are
removed and a new seat surface is evident. NOTE:
Remove only the amount of material necessary to
repair the seat surface.
face, apply a thin coating of Prussian Blue® paste to
the valve seat. If using an interference angle (46°)
apply black permanent marker to the entire valve
face (A).
a few times.
ENGINE
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