Installing Piston Rings; Cleaning/Inspecting/Measuring Cylinder Block - Arctic Cat Sno Pro 120 Service Manual

Installing Piston Rings

1. Install a thin oil ring, oil ring expander, and thin oil
ring in the bottom groove of the piston. Stagger the
end gaps of the upper and lower thin oil rings until
they are on directly opposite sides of the piston.
2. Install the #2 compression ring so the letters on the
top surface of the ring face the dome of the piston.
3. Install the #1 compression L-ring into the top groove
with the face of the ring directed upward.
4. Rotate the rings until the ring end gaps are 120° from
one another.
CAUTION
Incorrect installation of the piston rings will result in
engine damage.
MEASURING CONNECTING ROD
SMALL END BORE INSIDE
DIAMETER
1. Using a small bore gauge, measure the connecting
rod small end bore inside diameter.
2. Measurement must be within 0.866-0.867 in. for the
non-turbo and 0.945-0.946 in. for the turbo.
 NOTE: Check piston pin, connecting rod small end
bore, and piston bore for wear or damage paying par-
ticular attention to condition of small end bore bush-
ing. If pin, connecting rod small end bore, or piston
bore is badly worn or damaged, replace pin, connect-
ing rod, or piston.
Cleaning/Inspecting/Measuring
Cylinder Block
1. Wash the cylinder block in parts-cleaning solvent.
2. Check the head gasket surface of the cylinder for dis-
tortion.
3. Using a straightedge and feeler gauge, check surface
at a total of 6 locations. If distortion limit exceeds
0.002 in., replacement of the block will be necessary.
741-619A
4. Inspect the cylinder bore for minor scoring or scuff-
ing.
5. Hone the cylinder to produce a 45° crosshatch using
the appropriate Ball Hone and honing oil.
6. Wash the cylinder block thoroughly with hot soapy
water; then rinse with hot water.
7. Blow dry the cylinder block with compressed air and
immediately apply oil to all of the cylinder surfaces.
CRANKSHAFT RUNOUT
1. Support the crankshaft using a set of V Blocks; use a
dial indicator to read crankshaft runout.
 NOTE: The contact point of the dial indicator should
be on either side of the oil port hole of the center
crankshaft journal and to the outside of the oil port
ZJ057
hole on the MAG and PTO end of the crankshaft.
2
ZJ056
ZJ059
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