Snowmobile Arctic Cat 2-Stroke (2007 year). Manual - part 27

2-94

CM155A

„NOTE: For assembling purposes, note that the
positioning of the bypass/check valve is directed
up.

CM157A

18. Remove the six screws securing the water pump

cover to the crankcase and remove the cover.

Account for the O-ring gasket and the alignment

pins.

CM156A

19. Remove the cap screw securing the water pump

impeller; then slide the impeller free of the shaft.

20. Prior to turning the engine upside down on the 800

cc, remove the two crankcase Allen-head cap

screws from the water pump side of the engine;

then remove the two cap screws from the magneto

housing. On the 1000 cc, remove the one crank-

case Allen-head cap screw located above the ther-

mostat housing.

21. Turn the engine upside down on support blocks,

cut the cable tie, and remove the coolant tempera-

ture sensor switch.

22. With its bottom side up on two support blocks,

remove the cap screws securing the crankcase

halves.

„NOTE: The end bearings are not pressed onto
the crankshaft.

23. Separate the crankcase halves by installing two

crankcase cap screws in opposite corners leaving

the heads approximately 6 mm (1/4 in.) out. Using

a plastic hammer and lifting on the ends of the

crankshaft, tap on each cap screw head until the

case halves separate. Remove the cap screws.

CM158

24. Lift the bottom half of the crankcase off the top

half.

25. Lift the crankshaft free from the top half of the

crankcase and slide the crankshaft oil seals off the

crankshaft. Account for the C-ring. Remove the

bearing retaining pins and account for the crank-

case dowel pins.

26. Remove the oil-injection pump/water pump drive-

shaft from the lower crankcase half. Account for

the thrust washer on the outer end of the shaft.

! CAUTION

DO NOT drive any tool between halves to separate
the crankcase. Damage to the sealing surfaces will
result.

! CAUTION

Care must be taken to not allow the connecting rods
to drop onto the sealing surface of the bottom case
half.

2-95

2

CM159A

„NOTE: Do not replace the inner seals unless the
water pump shows signs of leaking coolant out of
the small bleed hole in the bottom half of the
crankcase. If a water pump seal is to be replaced,
use the Water Pump Bearing and Seal Kit (p/n
0644-084).

27. Place the crankcase on the bench with the water

pump side down. Using the long seal driver, drive

the mechanical water pump seal from the crank-

case.

FC036

28. Using a pair of snap ring pliers, remove the snap

ring securing the inner seal in the crankcase.

29. Using the hooked end of the tool, pull the inner

seal free of the crankcase.

30. Using the hooked end of the tool, pry the seal ring

from the backside of the water pump impeller.

AN327D

Servicing Top-Side 

Components 

Many services can be performed without removing the

engine. Some components may vary from model to

model. The technician should use discretion and sound

judgment when removing and installing components.

„NOTE: Some photographs used in this sub-sec-
tion are used for clarity purposes only and are not
designed to depict actual conditions.

REMOVING TOP-SIDE 

COMPONENTS

To access top-side components, use the following pro-

cedure:

1. Disconnect the exhaust temperature sensor; then

cut the cable tie securing the sensor harness to the

APV cable.

2. Remove the expansion chamber and resonator and

account for the springs, hairpin clip, and the tab

washer; then remove the exhaust manifold.

CM186

3. Drain the engine coolant (see Liquid Cooling Sys-

tem - Section 3).

4. Remove the cap screws securing the side-plate

brace and steering support to the chassis; then

remove the side-plate brace.

CM133A

2-96

CM132A

5. Remove the cap screws securing the APV assem-

blies to the cylinders; then remove the APV

assemblies and set them aside.

„NOTE: For installing purposes, note that the APV
exhaust valves and gaskets are directional.

CM187

„NOTE: At this point on the 800 cc, remove the
spark plugs (A) to gain access to the cylinder head
cap screws; then disconnect the knock sensor
plug-in (B).

CM188A

6. Remove the cap screws securing the cylinder

head; then lift the front of the head and remove the

O-rings.

CM189

CM190

7. Carefully lift and turn the cylinder head to gain

access to the hose clamp securing the coolant hose

to the cylinder head; then loosen the clamp.

Remove the coolant hose and breather hose con-

nected to the cylinder head.

CM191A

„NOTE: On the 1000 cc, remove the coolant
bypass hoses from the cylinders.

8. Remove the cap screws and nuts securing the cyl-

inders to the crankcase; then using a soft hammer,

gently tap the cylinders and remove from the

crankcase by lifting them straight up off their

studs. Account for gasket(s) and alignment pins.

2-97

2

CM192

„NOTE: If servicing the MAG-side only, the PTO-
side cylinder must be removed.

„NOTE: After the cylinders have been removed, it
is advisable to cover the crankcase to avoid com-
ponents falling into the crankcase.

9. Remove the PTO-side piston-pin circlip from the

PTO-side piston; then remove the PTO-side pis-

ton-pin circlip from the MAG-side piston.

10. Using Piston Pin Puller (p/n 0644-328) and

Medium Extractor Nut (p/n 0643-074), remove the

piston pins from both pistons.

CM193

„NOTE: The piston pins must be removed from the
PTO-side of the piston.

„NOTE: For proper assembly, keep all MAG-side
components and all PTO-side components sepa-
rated. Assemble them on their proper sides.

11. Lift the pistons clear of the connecting rods and

remove the small-end connecting-rod bearings

(account for two washers); then remove the piston

rings. Keep each piston with its rings; keep each

piston pin and bearing together as a set.

CM151

„NOTE: Place a suitable length of rubber hose
around the connecting rods. This will prevent the
connecting rods from damaging the crankcase.

„NOTE: For servicing procedures, see Cleaning
and Inspecting Engine and Measuring Critical
Components in this sub-section.

INSTALLING TOP-SIDE 

COMPONENTS

„NOTE: Critical torque specifications are located
in the Assembly Schematics sub-section of this
section.

1. Place the cylinder base gasket and alignment pins

into position on the crankcase.

2. Install the piston rings on each piston so the letter

on the top (inclined surface) of each ring faces the

dome of the piston.

! CAUTION

When removing a cylinder, be sure to support the pis-
ton to prevent damage to the crankcase and piston.

! CAUTION

Do not use the large extractor nut to remove the pin
or damage to the piston may occur.

! CAUTION

DO NOT use any type of punch to drive the piston
pin free of the piston; damage may result. Use a pis-
ton-pin puller only.