Snowmobile Arctic Cat (2004 year). Manual - part 20

2-67

2. Drive a chisel or bearing splitter between the

bearing race and crankshaft counterweight until
the bearing is spread far enough to install the jaws
of the crankshaft bearing remover.

3. Place the protective cap on the crankshaft end;

then using the Crankshaft Bearing Remover (p/n
0144-302), remove the bearing from the end of the
crankshaft. Account for any shim(s). Note the
position of the dowel pin hole.

AN068D

4. On certain models, the PTO-side bearing may be

removed simply by sliding the bearing off the PTO
end.

AN151A

NOTE: On certain models, the end bearings are

not pressed onto the crankshaft. The bearings can
be removed simply by sliding them off the crank-
shaft.

5. Inspect the crankshaft bearing area for wear. If any

wear is noted on either end, replace the crankshaft
end.

INSTALLING OUTER
CRANKSHAFT BEARINGS

NOTE: On certain models, steps 1-3 are for

installing the MAG-side bearing.

1. Wrap a thick towel around the crankshaft; then

secure the crankshaft vertically in a vise.

2. Heat the bearing either by placing the entire

bearing in a pan of oil on a hot plate or by
squirting oil into the bearing and using a propane
torch to heat the inner race of the bearing until a
slight smoke is noted coming from the bearing.

3. Place any shims removed during disassembly onto

the crankshaft; then slide the bearing onto the
crankshaft making sure the dowel-pin hole in the
outer race is properly positioned and will align
with its hole and pin in the crankcase.

4. On certain models, slide the PTO-side bearing

onto the PTO end making sure the dowel-pin hole
will align with the hole and pin in the crankcase.

NOTE: On certain models, install the bearings by

sliding each bearing onto the crankshaft making
sure the dowel-pin hole in the outer race is prop-
erly positioned and will align with its hole and pin
in the crankcase.

AN151A

REED VALVE ASSEMBLY

1. Inspect the reed valves, stoppers, and valve blocks

for cracks or any deterioration.

AQ046

2. Wash the reed valves, stopper, and cage assembly

in parts-cleaning solvent and blow dry.

! CAUTION

DO NOT overheat the bearing.

2-68

3. Inspect the reed stopper height. Using a caliper,

measure the distance from the seat to the bottom
outer tip edge of the stopper. Measurement must
not exceed specifications. If measurement is not
within specifications, either bend or replace the
reed stopper.

AJ156

4. Inspect the reed-to-seat clearance. Using a feeler

gauge, measure the clearance. Clearance must be
less than 0.20 mm (0.008 in.). If clearance is not
within specifications, replace the reed valve.

5. To assemble, place the reed valves on the cage

with its clipped corner positioned to the lower
right hand corner of the cage. Place the reed
stopper assembly into position and secure with the
three screws coated with red Loctite #271.

AQ047

Measuring Critical

Components

NOTE: Critical engine component specifications

can be found at the beginning of this sub-section.

CYLINDER TRUENESS

1. Measure each cylinder in the three locations from

front to back and side to side for a total of six
readings.

FC044

2. The trueness (out-of-roundness) is the difference

between the highest and lowest reading.
Maximum trueness (out-of-roundness) must not
exceed specifications.

0725-586

PISTON SKIRT/CYLINDER CLEARANCE

1. Measure each cylinder front to back about 2.5 cm

(1 in.) from the bottom of each cylinder.

2. Measure the corresponding piston skirt diameter at

a point 1 cm (0.394 in.) above the piston skirt at a
right angle to the piston-pin bore. Subtract this
measurement from the measurement in step 1. The
difference (clearance) must be within
specifications.

AC091

CYLINDER TRUENESS LIMIT (max)

in.

0.10

0.004

2-69

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
specifications.

FC045

PISTON PIN AND PISTON-PIN BORE

1. Measure the piston pin diameter at each end and in

the center. Acceptable piston pin measurement
must be within specifications. If any measurement
varies by more than 0.02 mm (0.001 in.), the
piston pin and bearing must be replaced as a set.

AN056

2. Insert a snap gauge into each piston-pin bore; then

remove the gauge and measure it with a
micrometer. The diameter measurement must be
within specifications. Take two measurements to
ensure accuracy.

AC092

CONNECTING-ROD SMALL END BORE

1. Insert a snap gauge into each connecting-rod small

end bore; then remove the gauge and measure it
with a micrometer.

AN061

2. The diameter measurement must be within

specifications.

CRANKSHAFT RUNOUT

1. Using the V Blocks (p/n 0644-022), support the

crankshaft on the surface plate.

NOTE: The V blocks should support the crank-

shaft on the outer bearings.

2. Mount a dial indicator and base on the surface

plate. Position the indicator contact point against
the crankshaft distance F (PTO-end) from the
crankshaft end. Zero the indicator and rotate the
crankshaft slowly. Note the amount of crankshaft
runout (total indicator reading).

NOTE: For runout distance specifications, see

Engine Information sub-section.

3. Position the indicator contact point against the

crankshaft distance D (MAG-end) from the
crankshaft end. Zero the indicator and rotate the
crankshaft slowly. Note the amount of crankshaft
runout (total indicator reading).

2-70

FC046

4. Position the indicator contact point against the

crankshaft at point E (center). Zero the indicator
and rotate the crankshaft slowly. Note the amount
of crankshaft runout (total indicator reading).

5. If runout exceeds specifications at any of the

checkpoints, the crankshaft must be either
straightened or replaced.

Assembling Engine

Table of Contents

370/440 cc Models ................................................ 2-70
550 cc Model......................................................... 2-74
570 cc Models ....................................................... 2-79
600 cc Standard Engine Model ............................. 2-87
800/900 cc Models ................................................ 2-92
500/600/700 cc “Laydown” Engine Models ........... 2-99

Assembling Engine

(370/440 cc Models)

NOTE: The use of new gaskets and seals is rec-

ommended when assembling the engine.

NOTE: When the use of a lubricant is indicated,

use Arctic Cat 50:1 Injection Oil.

1. Install the C-ring and the five bearing retaining

pins into the lower crankcase half.

2. Lubricate the inner lips of the crankshaft oil seals

with grease; then slide the seals onto the
crankshaft making sure the spring side of each seal
faces the center of the crankshaft.

AC087

3. Apply oil to the crankshaft bearings; then install

the dowel pins, C-ring, and crankshaft into the
lower crankcase half. Be sure the alignment hole
in each bearing is positioned over its respective
bearing retaining pin in the crankcase; then seat
the crankshaft.

AB091

NOTE: Make sure the crankshaft center seal is

properly positioned in the groove of the lower
crankcase half.

NOTE: To check the bearing for proper position,

place the point of a sharp tool into the dimple
found in the bearing race. Strike the tool with the
palm of the hand in either direction. If the bearing
moves, it isn't positioned correctly and must be
rotated until it drops onto the dowel pin.

4. Apply a thin coat of Three Bond Sealant (p/n

0636-070) to the crankcase sealing surfaces.

5. Assemble the crankcase halves making sure the

crankcase dowel pins are properly positioned and
the end seal tab will not block the oil transfer port
in the upper crankcase half.

! CAUTION

If the bearings are not properly seated during
assembly, the crankcase halves will not seal
tightly and engine damage will result.

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