Polaris R09VA17AA, Service Manual

Page: 68 / 187

3.24
ENGINE
5. Record measurements. If cylinder is tapered or out of round
beyond specification, the cylinder must be honed, bored or
replaced.
Cylinder Hone Selection / Honing Procedure
Cylinders may be wet or dry honed depending upon the hone
manufacturer’s recommendations. Wet honing removes more
material faster and leaves a more distinct pattern in the bore.
Honing to Deglaze
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 sufficiently deglazed,
and to check for correct cross-hatch.
NOTE: Do not
allow cylinder to heat up during honing.
• After honing has been completed, inspect cylinder for
thinning or peeling.
IMPORTANT: Clean 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. 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 to prevent the formation of surface rust.
If cylinder wear or damage is excessive, it will be necessary to
replace the cylinder. Hone only enough to deglaze the outer
layer of the cylinder bore.
Piston Inspection
1. Measure piston outside diameter at a point 7 mm up from
the bottom of the piston at a right angle to the direction of
the piston pin.
2. Subtract this measurement from the maximum cylinder
measurement obtained earlier.
= In. / mm.
Cylinder Taper:
Limit: .002” (.05 mm) Max.
Cylinder Out of Round:
Limit: .002” (.05 mm) Max.
CAUTION
A hone which will straighten as well as remove
material from the cylinder is very important.
Using a common spring loaded glaze breaker for
honing is not advised. Polaris recommends
using a rigid hone or arbor honing machine.
= In. / mm.
Piston to Cylinder Clearance
Std: .00039- .0015” (0.01- 0.04 mm)
Limit: .0039” (.1 mm)
EXAMPLE OF CROSS HATCH PATTERN
Piston
Piston Pin
7mm
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