Page 175 - Manual Oficina Polaris Sportsman 570 2014 a 2016

ENGINE / COOLING SYSTEM

7. Remove valve and check where the Prussian Blue Intake Seat Cutter Diameter:
indicates seat contact on the valve face. The valve 1.172 in. (29.793 mm)
seat should contact the middle of the valve face or
slightly above, and must be the proper width.
NOTE
When using an interference angle, the seat contact
point on the valve will be very narrow, and is a normal
condition. Look for an even and continuous contact
point all the way around the valve face (A).
3

Valve Seat Angles
1 - 17°
2 - 45°
3 - 70°
Exhaust Seat Cutter
Diameter:
0.956 in. (24.294 mm)

MEASUREMENT
Valve Seat Width:
8. Clean all filings from the area with hot soapy water.
Intake: Rinse and dry with compressed air.
Std.: .0393" (1.00 mm)
9. Lubricate valve guides with clean engine oil and
Service Limit: .0551" (1.4 mm)
apply oil or water based lapping compound to the
face of the valve.
Exhaust: NOTE
Std.: .0393” (1.00 mm) Lapping is not required if an interference angle
Service Limit: .0758" (1.9 mm) reconditioning method is used.

* If the indicated seat contact is at the top edge of the 10. Insert the valve into its respective guide and lap
valve face and contacts the margin area (B) it is too using a lapping tool or a section of fuel line
high on the valve face. Use the 30° cutter to lower connected to the valve stem.
the valve seat. 11. Rotate the valve rapidly back and forth until the cut
* If too low, use the 70° cutter to raise the seat. When sounds smooth. Lift the valve slightly off of the seat,
contact area is centered on the valve face, measure rotate 1/4 turn, and repeat the lapping process. Do
seat width. this four to five times until the valve is fully seated,
* If the seat is too wide or uneven, use both top and and repeat process for the other valves.
bottom cutters to narrow the seat.
12. Thoroughly clean cylinder head and valves.
* If the seat is too narrow, widen using the 45° cutter
and re-check contact point on the valve face and
seat width after each cut.

9926803 R06 - 2014-2016 Sportsman 325 / ETX / 450 HO / 570 Service Manual 3.53
© Copyright Polaris Industries Inc.