Polaris PREDATOR 2003 Service Manual page 84

ENGINE
CYLINDER HONE SELECTION
AND HONING PROCEDURE
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 for nicasil cylinders. Polaris recommends
using a rigid hone or arbor honing machine.
Cylinders may be wet or dry honed depending upon
the hone manufacturer's recommendations.
honing removes more material faster and leaves a
more distinct pattern in the bore.
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.
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
instructions, or these guidelines:
Use a motor speed of approximately
G
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
G
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,
G
inspect cylinder for thinning or
peeling.
Wet
hone manufacturer's
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.
EXAMPLE OF CROSS HATCH PATTERN
CYLINDER HEAD VALVE
GUIDE / SEAT RECONDITION
CYLINDER HEAD RECONDITIONING NOTES
Valve Seat Inspection
Inspect valve seats 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.
NOTE: Servicing the valve guides and valve seats
requires special tools and a thorough knowledge of
reconditioning techniques. Follow the instructions
provided in the cylinder head service tool kit.
CAUTION: Wear the proper safety equipment when
performing cylinder head service.
replacement will require heating of the cylinder head.
Wear safety gloves to prevent burns.
VALVE GUIDE REMOVAL / INSTALLATION / REAM
1. Remove all carbon deposits from the combustion
chamber, valve seat and valve guide area before
attempting to remove valve guides. CAUTION:
Carbon deposits are extremely abrasive and may
damage the valve guide bore when guides are
removed.
2. Place new valve guides in a freezer for at least 15
minutes while heating cylinder head.
3. Heat cylinder head in an oven or use a hot plate to
bring cylinder head temperature to 212 F (100
C). CAUTION: Do not use a torch to heat
cylinder head or warpage may result from uneven
heating. Head temperature can be checked with
a pyrometer or a welding temperature stick.
4. When thoroughly heated, place cylinder head on
blocks of wood which will allow the old guides to
be removed.
Valve guide
3.41