Honing Procedure; Honing To Over Size (340/550/500 Fuji Engines Only); Cleaning The Cylinder After Honing; Piston Inspection - Polaris 340 CLASSIC 2006 Manual

HONING PROCEDURE

1. Wash the cylinder with solvent.
2. Clamp the cylinder in a soft jawed vise by the exhaust port
studs.
3. Place hone in cylinder and tighten stone adjusting knob
until stone contacts the cylinder walls (DO NOT
OVERTIGHTEN). Cylinders may be wet or dry honed
depending on the hone manufacturer's recommendations.
Wet honing removes more material faster and leaves a
more distinct pattern in the bore. Using a 1/2" (13 mm)
drill motor rotating at a speed of 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
to prevent edge loading and always bring the stone
approximately 1/2" (1.3 cm) beyond the bore at the end of
each stroke.
4. Release the hone at regular intervals to inspect bore size
and finish.
HONING TO OVER SIZE (340/550/500 FUJI
ENGINES ONLY)
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.
For oversize honing always wet hone using honing oil and a
coarse roughing stone. Measure the new piston at room
temperature (see piston measurement) and rough hone to the
size of the piston or slightly larger. Always leave .002" - .003"
(.05 - .07 mm) for finish honing. Complete the sizing with fine
grit stones to provide the proper cross-hatch finish and
required piston clearance.
Inspect cylinder for taper and out-of-round. Taper or out-of-
round on the finished bore should not exceed .0004"
(.002mm).
NOTE: Portable rigid hones are not recommended
for oversizing cylinders, cylinder boring, and finish
honing. The use of an arbor type honing machine is
recommended. Always check piston to cylinder
clearance and piston ring installed gap after boring/
honing is complete.

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 Premium 2
Cycle Lubricant.
NOTE: Always check piston to cylinder clearance
and piston ring installed gap after honing or boring
is complete.

PISTON INSPECTION

Check piston for scoring or cracks in piston crown or pin area.
Excessive carbon buildup below the ring lands is an indication
of piston, ring or cylinder wear. For Libertyt engines,
measure piston outside diameter at a point 3/8" (10mm) up
from the bottom of the skirt at a 90_ angle to the direction of
the piston pin. For Fuji engines, measure piston outside
diameter at a point that is 1/2" (12.7mm) up form the bottom
of the skirt at a 90_ angle to the direction of the piston pin.
90 to pin
DOMESTIC ENGINES - Measure 3/8 (10.0mm)
up from bottom of skirt
FUJI ENGINES - Measure 1/2 (12.7mm) up
from bottom of skirt
NOTE: The piston is measured at this point to
provide an accurate piston to cylinder
measurements.
Subtract this measurement from the minimum cylinder
measurement (90_ to the pin) recorded previously when you
recorded the cylinder measurements. If clearance exceeds the
service limit, the cylinder should be re-bored and new pistons
and rings installed. Refer to piston to cylinder clearance limits
in the General Information section listed per model.
MAINTENANCE
3.7