Arctic Cat ZR4000 Service Manual page 66

NOTE: Make sure the smaller reading is 0.059 in. or

less.
CYLINDER TRUENESS
1. Measure each cylinder in the three locations from
front to back and side to side for a total of six read-
ings.
FC044
2. The trueness (out-of-roundness) is the difference
between the highest and lowest reading. Maximum
trueness (out-of-roundness) must not exceed 0.004
in.
0725-586
PISTON SKIRT/CYLINDER CLEARANCE
1. Measure each cylinder front to back about 1 in. from
the bottom of each cylinder.
2. Measure the corresponding piston skirt diameter at a
point 1 cm above the piston skirt at a right angle to
the piston-pin bore. Subtract this measurement from
the measurement in step 1. The difference (clear-
ance) must be within 0.0031-0.0041 in.
AC091
PISTON-RING END GAP
1. Place each piston ring in the wear portion above the
exhaust port of its respective cylinder. Use the piston
to position each ring squarely in each cylinder.
2. Using a feeler gauge, measure each piston-ring end
gap. Acceptable ring end gap must be within
0.008-0.016 in.
FC045
PISTON PIN
1. Measure the piston pin diameter at each end and in
the center. Acceptable piston pin measurement must
be within 0.8659-0.8661 in. If any measurement var-
ies by more than 0.001 in., the piston pin and bearing
must be replaced as a set.
IO012
CRANKSHAFT RUNOUT
1. Using the V Blocks, support the crankshaft on the
surface plate.
NOTE: The V blocks should support the crankshaft

on the outer bearings.
2. Mount a dial indicator and base on the surface plate.
Position the indicator contact point against the crank-
shaft location point A (PTO-end) from the crankshaft
end. Zero the indicator and rotate the crankshaft
slowly. Note the amount of crankshaft runout (total
indicator reading).
65