Valve Seat Reconditioning - Polaris RANGER RZR 170 Service Manual

ENGINE
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, front to back
and side to side.
7. Subtract valve stem measurement to obtain stem to
guide clearance. NOTE: Be sure to measure each
guide and valve combination individually.
8. Replace valve and/or guide if clearance is excessive.
NOTE: If valve guides are replaced, valve seats must
be reconditioned.
Reconditioning for procedure.

Valve Seat Reconditioning

Valve Seat Inspection
Inspect valve seat in cylinder head for pitting, burnt spots,
roughness, and uneven surface. If any of the above
conditions exist, the valve seat must be reconditioned. If
the valve seat is cracked the cylinder head must be
replaced.
Too
Uneven
Wide
Cylinder Head Reconditioning
NOTE: Servicing the valve guides and valve seats
requires special tools and a thorough knowledge of
reconditioning techniques.
Wear eye protection when
performing cylinder head service.
3.20
Refer to Valve
Good Too
Narrow
CAUTION
9923983 - 2012-2013 RZR 170 Service Manual
© Copyright 2012 Polaris Sales Inc.
Follow the manufacturers instructions provided with the
valve cutting kit (commercially available). Abrasive stone
seat reconditioning equipment can also be used. Keep
valves in order with their respective seat.
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 and the valve may overheat
and warp, resulting in burned valves.
1. Install pilot into valve guide.
Seat
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
circumference of the seat, rotate the pilot 180
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.

and