Snowmobile Arctic Cat 2-Stroke (2007 year). Manual - part 37

2-134

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 pis-

ton 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 microme-

ter. 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 specifi-

cations.

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 location point 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 location point specifications,
see Crankshaft Runout Specifications chart on
page 19 of this section.

3. Position the indicator contact point against the

crankshaft location point D (MAG-end) from the

crankshaft end. Zero the indicator and rotate the

crankshaft slowly. Note the amount of crankshaft

runout (total indicator reading).

FC046

4. Position the indicator contact point against the

crankshaft at location point E (center). Zero the

indicator and rotate the crankshaft slowly. Note

the amount of crankshaft runout (total indicator

reading).

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2

5. If runout exceeds specifications at any of the

checkpoints, the crankshaft must be either

straightened or replaced.

Assembling Engine

„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 Synthetic APV 2-Cycle Oil.

1. Apply a thin coat of grease to the inner seal lips of

the water pump seal.

2. Using the seal driver, position the inner water

pump shaft seal onto the seal driver and gently tap

the seal down into position.

„NOTE: Grease must be applied to the lips of the
inner seal before installation.

MS986A

„NOTE: The seal must be installed with its spring
side towards the crankshaft.

3. Install the snap ring securing the inner seal in the

crankcase.

MS415

4. Using the seal driver, carefully install the outer

water pump seal. Gently tap the seal down into

position until it seats itself against its flange.

MS988

5. Apply a thin coat of grease to the sealing surface

of the oil-injection pump/water pump driveshaft;

then place the Oil Seal Protector Tool (p/n 0644-

219) at the end of the shaft. Twist the driveshaft

clockwise as it is pushed through the oil and water

pump seals; then remove the tool. Position the

shim on the oil-injection pump end of the drive-

shaft.

FS191

6. Position the shim on the oil-injection pump end of

the driveshaft.

CM044

! CAUTION

Be very careful not to damage the seals when
installing the oil pump driveshaft. Be certain to use
the seal installation tool. Twist the driveshaft clock-
wise as it enters the seal area and while it is being
pushed through the seals.

2-136

7. Position the upper crankcase half upside-down on

two wooden blocks; then install the C-ring, the

four bearing retaining pins, and the two crankcase

dowel pins.

8. Place the PTO-side crankshaft bearing into posi-

tion making sure the bearing retaining pin hole is

positioned inward.

„NOTE: The bearing retaining pin hole is the hole
that doesn't go entirely through the bearing case.

CM043A

9. Lubricate the inner lips of the crankshaft oil seals

with grease; then slide the seals (and rubber spacer

on the 600 cc) onto the crankshaft making sure the

spring side of each seal faces the center of the

crankshaft.

„NOTE: There is a MAG-side seal and a PTO-side
seal.

10. Apply oil to the crankshaft bearings; then install

the crankshaft into the upper crankcase half. Be

sure the alignment hole in each bearing is posi-

tioned over its respective dowel pin in the crank-

case; then seat the crankshaft.

CM045A

„ 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.

11. Position the two center seal rings with their end

gaps 180° apart (up on one and down on the

other); then apply a thin coat of High-Temp Seal-

ant (p/n 0636-069) to the entire bottom half of the

crankcase sealing surface.

CM036A

FC071

„NOTE: Use only Arctic Cat High-Temp Sealant (p/
n 0636-069) to seal the crankcase halves.

12. Assemble the crankcase halves making sure that

the crankshaft gear and oil-injection pump drive-

shaft gears mesh. Rotate the crankshaft one full

turn to align the crankshaft gear and pump drive-

shaft.

13. Install the crankcase cap screws (coated with blue

Loctite #243) securing the crankcase halves. 

14. Tighten the three 6 mm cap screws to specifica-

tions and the ten 10 mm cap screws to specifica-

tions using the appropriate pattern shown.

! CAUTION

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

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2

0738-201

738-202A

„NOTE: On the 500 cc, secure the connecting rods
with rubber bands on the cylinder studs. On the
600 cc, secure the connecting rods with rubber
hoses.

15. Install the oil-injection pump retainer O-ring and

retainer.

FC082

16. Install the O-ring and the oil-injection pump mak-

ing sure the pump shaft slot and pump driven gear

shaft align. Secure with two screws (coated with

blue Loctite #243). Tighten the two screws to

specifications.

17. Position the ceramic/rubber seal retainer and seal

into the back side of the water pump impeller with

the ceramic face of the seal directed out.

CM168

18. Using both thumbs, press the seal into position

making sure its marked side is positioned towards

the rubber seal cup; then apply a thin coat of

grease to the seal outer surface.

CM169

19. Place the impeller into position and secure with a

cap screw and washer. Be sure the rubber side of

the washer is directed toward the impeller. Apply

blue Loctite #243 to the threads of the cap screw

and tighten to specifications.

20. Apply high-temperature sealant to the crankcase/

water pump cover seam; then install the dowel

pins into the crankcase.

! CAUTION

Be sure the oil-injection pump/water pump drive-
shaft is properly aligned with the slot of the oil-injec-
tion pump. The pump will be damaged if these two
components are not aligned.

500 cc

600 cc

! CAUTION

The rubber side of the washer, which secures the
impeller, must be positioned toward the impeller. If
installed incorrectly, a coolant leak will result.