Polaris 2012 Sportsman Forest 500 International, Руководство по обслуживанию

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3.13
ENGINE
3
9923412 - 2012 Sportsman 400/500 and EFI Tractor Service Manual
© Copyright 2011 Polaris Sales Inc.
Honing To Oversize
A finished cylinder should have a cross-hatch pattern to
ensure piston ring seating and to aid in the retention of the
fuel/oil mixture during initial break in. Hone cylinder
according to hone manufacturer’s instructions, or these
guidelines:
• Use a motor speed of approximately 300-500
RPM, run the hone in and out of the cylinder
rapidly until cutting tension decreases. Remember
to keep the hone drive shaft centered (or cylinder
centered on arbor) and to bring the stones
approximately 1/2” (1.3 cm) above and below the
bore at the end of each stroke.
• Release the hone at regular intervals and inspect
the bore to determine if it has been cleared, and to
check piston fit.
NOTE: Do not allow cylinder to
heat up during honing. The thinner areas of the
liner around the ports will expand causing uneven
bore.
• After honing has been completed inspect all port
opening areas for rough or sharp edges. Apply a
slight chamfer to all ports to remove sharp edges
or burrs, paying particular attention to the corners
of the intake and exhaust ports.
Cleaning the Cylinder After Honing
It is very important that the cylinder be thoroughly cleaned
after honing to remove all grit material. Wash the cylinder
in a solvent, then in hot, soapy water. Pay close attention
to areas where the cylinder sleeve meets the aluminum
casting (transfer port area). Use electrical contact cleaner
if necessary to clean these areas. Rinse thoroughly, dry
with compressed air, and oil the bore immediately with
Polaris 4 Cycle Lubricant.
CAUTION
If cylinder wear or damage is excessive, it will be
necessary to oversize the cylinder using a new oversize
piston and rings. This may be accomplished by either
boring the cylinder and then finish honing to the final bore
size, or by rough honing followed by finish honing.
CAUTION
For oversize honing, always wet hone using honing oil
and a coarse roughing stone. Measure the piston (see
piston measurement) and rough hone to the size of the
piston. Always leave .002 - .003" (.05 - .07 mm) for finish
honing. Refer to piston-to-cylinder clearance
specifications before honing. Complete the sizing with
fine grit stones to provide the proper cross-hatch finish
and required piston clearance.
EXAMPLE OF CROSS HATCH PATTERN