Tracker Off-Road XTR1000 Service Manual page 50

SNO-287
NOTE: If the existing rings will not be replaced with

new ones, note the location of each ring for proper
installation. When installing new rings, install as a
complete set only.
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 a new piston ring into a piston groove and measure
clearance between ring and ringland by using feeler
gauge. Measurement must be within the following speci-
fications. If clearance is out of specification, replace pis-
ton.
1st Ring
2nd Ring
SNO-288
0.35-0.45 mm (0.014-0.018 in.)
0.70-0.80 mm (0.028-0.031 in.)
0.10-0.35 mm (0.004-0.014 in.)
0.030-0.065 mm (0.0012-0.0026 in.)
0.02-0.055 mm (0.0008-0.0022 in.)
Measuring Piston Skirt/Cylinder
Clearance
1. Measure the cylinder bore using a gauge by taking
side-to-side and front-to-back measurements of the
cylinder. Then, find the average of the measure-
ments.
SNO-289
Cylinder Bore (C)
Taper Limit (T)
Out of Round (R)
SNO-290
"C" = maximum of D1 - D6
"T" = maximum of D1 or D2 - maximum of D5 or D6
"R" = maximum of D1 D3 or D5 - maximum of D2, D4, or D6
NOTE: If out of specification, replace the crankcase

and the piston and piston rings as a set.
Measuring Piston Skirt Diameter
1. Measure the piston skirt diameter (A) with a
micrometer. Be sure to measure 10.0 mm (0.39 in.)
from the bottom edge of the piston (B).
2. Piston skirt diameter must be within 79.95-79.96 mm
(3.1476-3.1480 in.).
80.000-80.010 mm (3.150-3.154
in.)
0.050 mm (0.0020 in.)
0.050 mm (0.0020 in.)
49