Polaris Magnum 2x4 Service Manual page 184

Engine Disassembly, Cont.
Valve Seat Reconditioning
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.
• If the contact area is less than 75% of the cir-
cumference of the seat, rotate the pilot 180 0
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 im-
proper installation and must be replaced. Be
sure the cylinder head is at the proper temper-
ature and replace the guide.
• 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 evi-
dent. NOTE: Remove only the amount of
material necessary to repair the seat surface.
5. To check the contact area of the seat on the valve
face, apply a thin coating of Prussian Blue™ paste to
the valve seat.
6. Insert valve into guide and tap valve lightly into place
a few times.
Polaris Industries Inc.
3.57
ENGINE
EH42PL/EH50PL Engine
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