Measuring Piston-Ring End Gap; Piston Ring/Groove Clearance; Measuring Piston Skirt/Cylinder Clearance; Measuring Piston Pin Diameter - Arctic Cat Sno Pro 120 Service Manual

Measuring Piston-Ring End Gap

(Installed)
1. Place each piston ring in the wear portion of the cyl-
inder. Use the piston to position each ring squarely in
the cylinder.
 NOTE: Remove any carbon; then clean the top of
the cylinder bore before inserting the piston rings.
2. Using a feeler gauge, measure each piston-ring end
gap. Acceptable ring end gap must be within the fol-
lowing specifications.
1st Ring
2nd Ring
Oil Rings

Piston Ring/Groove Clearance

 NOTE: Before checking, piston grooves must be
clean, dry, and free of carbon.
Fit new piston ring into piston groove and measure clear-
ance between ring and ringland by using feeler gauge.
Measurement must be within the following specifica-
tions. If clearance is out of specification, replace piston.
1st Ring
2nd Ring
Oil Rings
Measuring Piston Skirt/Cylinder
Clearance
1. Measure the cylinder front to back in six places using
a cylinder bore gauge. Record the largest number.
2. Measure the diameter of the corresponding piston at
a point 10 mm from the piston skirt edge at a right
angle to the piston-pin bore. Piston diameter must be
within 3.8568-3.8574 in. for the non-turbo and
3.8574-3.8580 in. for the turbo. If not, the piston
must be replaced. Subtract this measurement from
the measurement in step 1. Measurement must be
within 0.0011-0.0016 in. for the non-turbo and
0.0006-0.0010 in. for the turbo. If the determined
wear exceeds the limit indicated and the piston is
within tolerance, the cylinder block must be
replaced.
2-124
0.0059-0.0138 in.
0.0118-0.0177 in.
0.0078-0.0275 in.
0.0008-0.0035 in.
0.0008-0.0024 in.
0.0024-0.0059 in.
0738-532
Measuring Piston Pin Bore
Diameter
 NOTE: It may be necessary to use Piston Pin Puller
to remove the piston pins.
1. Insert an inside dial indicator into the piston-pin
bore. Take two measurements to ensure accuracy.
2. Piston pin bore must be within 0.8662-0.8664 in. for
the non-turbo and 0.9449-0.9451 in. for the turbo.

Measuring Piston Pin Diameter

Measure the piston pin diameter at each end and in the
center. Measurement must be within 0.8658-0.8661 in.
for the non-turbo and 0.9447-0.9449 in. for the turbo. If
measurement is not within specifications, the piston pin
must be replaced.
GEN-0033
ATV-1069
ATV-1070