Snowmobile Arctic Cat (2004 year). Manual - part 16

2-51

2

AP134

10. Remove the cap screws securing the valves to the

cylinders; then remove the APV assemblies and
set them aside.

„

NOTE: The following two photographs are for

clarity purposes only. These models may vary
slightly.

AP120

AP121

11. Remove the three cap screws securing the

thermostat cap; then remove cap, rubber gasket,
and thermostat.

12. Remove the cap screws securing the thermostat

manifold to the cylinder heads. Remove the
manifold and discard the gaskets.

AP135

13. Remove the spark plugs.

14. Remove the cap screws and O-rings securing each

head; then separate each head from each cylinder.
Account for two O-rings beneath each head.

„

NOTE: Mark each cylinder head, cylinder, and

piston and keep together as an assembly. Mark the
MAG cylinder components #1 and the PTO cylin-
der components #2.

AP136

„

NOTE: If servicing the intake flanges, remove

them at this time.

15. Remove the four cylinder base nuts and four

flange cap screws securing the cylinders to the
crankcase. Account for four flat washers and lock
washers. Using a rubber hammer, gently tap on the
side of each cylinder to free it from the crankcase.

AP137

2-52

16. Slowly lift each cylinder straight up and free of the

studs. Grasp the connecting rod and piston as the
cylinder clears the piston to prevent the rod from
dropping against the crankcase. Remove and save
the cylinder base gaskets.

AP138

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

PTO-side piston; remove the MAG-side piston-pin
circlip from the MAG-side piston.

AP140

18. Using the Piston Pin Puller (p/n 0644-328),

remove the piston pins from both pistons.

AP141

„

NOTE: For proper assembly, keep all MAG-side

components and all PTO-side components sepa-
rated. Assemble them on their proper sides.

19. Lift the pistons clear of the connecting rods and

account for two washers. Remove the small-end
connecting-rod bearings; then remove the piston
rings. Keep each piston with its rings; keep each
piston, pin, and bearing together as a set.

AQ059

20. Remove the four cap screws securing the PTO-end

plate to the crankcase; then remove the plate.

AP142

21. Remove the intake manifold and reed block

assemblies.

22. Remove either lower union bolt securing the lower

check valve assembly; then remove the two cap
screws securing the oil-injection pump to the
crankcase. Remove the pump, retainer, and two O-
rings.

! CAUTION

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

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2

AP143

23. Remove the six cap screws securing the water

pump cover to the crankcase. Remove the cover
and O-ring seal. Account for two dowel pins.

AP145

„

NOTE: Do not remove the water pump impeller

or the impeller shaft unless necessary. Only
remove impeller and shaft if there are signs of
coolant leakage from the small hole located in the
bottom of the crankcase directly behind the water
pump housing.

24. Lay the engine on its side and remove the cap

screws securing the crankcase halves. Note the
position of the different-sizes cap screws for
assembling.

AP146

„

NOTE: On 800 cc models, the magneto case

must be removed prior to separating the crank-
case halves. 

25. 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 tipped hammer, tap on each cap screw
head until the case halves separate; then remove
the two cap screws. Lift the top half of the
crankcase off the bottom half. Grasp the
connecting rods as the top half of the crankcase is
removed. Do not allow them to drop onto the
sealing surface of the bottom case half.

26. Lift the crankshaft free from the crankcase half

and slide the crankshaft oil seals off the ends of the
crankshaft. Account for the C-ring. Slide the
bearings off the crankshaft. Remove and account
for the four bearing retaining pins and the two
crankcase dowel pins from the crankcase.

AP148A

A. Remove the O-ring from the oil-injection pump

retainer. Slide the retainer into position on the
shaft in the lower half of the crankcase.

B. While holding the retainer tight against the

crankcase, rotate the shaft. Bearing rotation
must feel smooth.

! CAUTION

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

! CAUTION

DO NOT remove the water pump impeller or shaft
unless necessary. The shaft and impeller should
only be removed from the lower crankcase half
when there is a coolant leakage problem or a
rough inner bearing. To inspect for either
condition, follow steps A through D.

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AJ044

C. If any roughness is felt, remove the retainer and

inspect its bearing by turning it several
revolutions. If it is smooth, the shaft must then
be removed and the inner bearing inspected.
Turn inner bearing by hand. If any roughness is
felt, replace the inner bearing.

D. Check the bottom of the water pump housing

for any signs of coolant leakage. The small
hole, located on the bottom of the crankcase
directly behind the water pump housing, will
show coolant stains if the seal has any leakage
problems. If stains or any signs of leakage are
present, remove impeller and shaft and replace
seals.

AJ045

„

NOTE: For instructions on bearing and seal

replacement, see the appropriate Assembling
Engine sub-section of this manual. Complete
steps 27-32 only if there is a bad seal or shaft bear-
ing.

27. Remove the cap screw securing the impeller to the

shaft.

AJ046

28. Remove the oil-injection pump/water pump

driveshaft from the lower crankcase half. Account
for the thrust washer on the outer end of the shaft.

AN324D

„

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).

29. 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
crankcase.

AN325D

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

ring securing the inner seal in the crankcase.

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

seal free of the crankcase.