Polaris Magnum 2x4 Service Manual page 185

ENGINE
EH42PL/EH50PL Engine
Engine Disassembly, Cant.
7. Remove valve and check where the Prussian Blue™
indicates seat contact on the valve face. The valve
seat should contact the middle of the valve face and
must be the proper width.
• If the indicated seat contact is too high on the
valve face, use the 30° or 31 0 cutter to lower
the valve seat.
If too low use the 60° or 75° cutter to raise the
seat. When contact area is centered on the
valve face, measure seat width.
If the seat is too wide or uneven, use both top
and bottom cutters to narrow the seat.
If the seat is too narrow, widen using the 46°
cutter and re-check contact pOint on the valve
face and seat width after each cut.
8. Clean aI/ filings from the area with hot soapy water,
rinse, and dry with compressed air.
9. Lubricate the valve guides with clean engine oil, and
apply oil or water based lapping compound to the face
of the valve.
10. Insert the valve into its respective guide and lap using
a lapping tool or a section of fuel line connected to the
valve stem.
11. Rotate the valve rapidly back and forth until the cut
sounds smooth. Lift the valve slightly off of the seat,
rotate 114 turn, and repeat the lapping process. Do
this four to five times until the valve is fully seated, and
repeat process for the other three valves.
12. Remove oil passage blind plug and thoroughly clean
cylinder head and valves.
7/96 3.58
Seating
Surface
Polaris Industries Inc.