Snowmobile Arctic Cat (2008 year). Manual - part 17

2-5

2

AB015

11. Install a protective cap onto the end of the crank-

shaft.

„NOTE: A suitable protective cap can be made by
welding a 1/8 in. plate on one side of a spare fly-
wheel nut.

AB022

12. Using the Flywheel Puller or suitable equivalent,

remove the flywheel from the crankshaft by tight-

ening the puller bolt, striking the head of the puller

bolt with a hammer, and tightening again. Repeat

procedure until the flywheel is free. Account for

the key in the end of the crankshaft.

„NOTE: To ensure the cleanliness of the flywheel
magnets, place the flywheel (with the magnets fac-
ing upward) on a clean bench.

13. Scribe a reference line on the stator plate and

crankcase to aid in assembly; then remove the two

Allen-head cap screws, lock washers, and washers

securing the stator plate.

„NOTE: The two stator plate Allen-head cap
screws had Loctite applied to the threads during
assembly. Before removing them, apply a sharp
blow to the head of each screw to break the Loctite
loose. If this isn’t done, the screws can be very dif-
ficult to remove.

AB026

14. Remove the stator plate from the engine.

15. Remove the screws, lock washers, and washers

securing the oil-injection pump to the crankcase;

then remove the pump, retainer, shim, and gear.

Account for two gaskets.

AB018

16. Remove the spark plugs.

17. Remove the eight nuts, lock washers, and washers

securing the cylinder heads to the cylinders. Note

the position of the different-sized nuts. Remove

the heads and account for two gaskets and four

dowel pins.

B563

! CAUTION

To prevent damage to the crankshaft, thread a pro-
tective cap onto the crankshaft. The puller must bot-
tom on the cap and not on the crankshaft. Also, do
not thread puller bolts more than 1/2 in. into the fly-
wheel. Damage to the coils may result.

2-6

18. Using a rubber hammer, gently tap the cylinders

and remove from the crankcase by lifting them

straight up off their studs. Discard the two gaskets.

Account for two dowel pins.

19. Using a felt-tipped marker, mark an M on the

MAG-side head, cylinder, and piston and a P on

the PTO-side head, cylinder, and piston.

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

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

PTO-side piston; remove the MAG-side piston-pin

circlip from the MAG-side piston.

A829

21. Using the Piston Pin Puller, remove the piston pins

from both pistons.

A830

22. Lift the pistons clear of the connecting rods and

remove the small end connecting-rod bearings;

then remove the piston rings. Keep each piston

with its rings, piston pin, and bearing together as a

set.

„NOTE: Place rubber bands over the connecting
rods and around the cylinder studs. This will keep
the connecting rods from damaging the crank-
case.

B160

23. Remove the cap screws securing the crankcase

halves. Note the position of the different-sized cap

screws.

A831

24. Separate the crankcase halves by installing two

crankcase cap screws in diagonal corners leaving

the heads approximately 1/4 in. out. Using a plas-

tic hammer, tap on each cap screw head until the

halves separate. Remove the cap screws.

25. Remove the rubber bands holding the connecting

rods; then separate the crankcase halves. Account

for the two dowel pins. Lift the crankshaft free

from the crankcase half and slide the two crank-

shaft seals off the crankshaft. Account for the C-

ring and five bearing retaining pins.

! CAUTION

When removing a cylinder, make sure to support the
pistons so they will not be damaged.

! 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.

! CAUTION

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

2-7

2

Cleaning and Inspecting 

Engine

„NOTE: Whenever a part is worn excessively,
cracked, or damaged in any way, replacement is
necessary.

CYLINDER HEAD

1. Using a non-metallic carbon removal tool, remove

any carbon buildup from the combustion chambers

being careful not to nick, scrape, or damage the

combustion chambers or the sealing surfaces.

2. Inspect the spark-plug holes for any damaged

threads.

3. Place the cylinder heads on a Surface Plate cov-

ered with #400 grit wet-or-dry sandpaper. Using

light pressure, move each cylinder head in a figure

eight motion. Inspect the sealing surface for any

indication of high spots. A high spot can be noted

by a bright metallic finish. Correct any high spots

before assembly by continuing to move the cylin-

der head in a figure eight motion until a uniform

bright metallic finish is attained.

MD2498

CYLINDERS

1. Using a non-metallic carbon removal tool, remove

carbon buildup from the exhaust ports.

2. Wash the cylinders in parts-cleaning solvent.

3. Inspect the cylinders for pitting, scoring, scuffing,

and corrosion. If marks are found, repair the sur-

face with a Ball Hone and honing oil.

„NOTE: To produce the proper 45° crosshatch
pattern, maintain a low drill RPM. If honing oil is
not available, use a lightweight, petroleum-based
oil. Thoroughly clean the cylinders after honing
using detergent soap and hot water and dry with
compressed air; then immediately apply oil to the
cylinder bores. If a bore is severely damaged or
gouged, the cylinder will have to be replaced.

4. Place the head surface of each cylinder on the sur-

face plate covered with #400 grit wet-or-dry sand-

paper. Using light pressure, move each cylinder in

a figure eight motion. Inspect the surface for any

indication of high spots. A high spot can be noted

by a bright metallic finish. Correct any high spots

before assembly by continuing to move the cylin-

der in a figure eight motion until a uniform bright

metallic finish is attained.

PISTON ASSEMBLY

1. Using a non-metallic carbon removal tool, remove

the carbon buildup from the dome of each piston.

2. Take an old piston ring and snap it into two pieces;

then grind the end of the old ring to a 45° angle

and to a sharp edge. Using the sharpened ring as a

tool, clean carbon from the ring-grooves. Be sure

to position the ring with its tapered side up.

3. Inspect each piston for cracks in the piston pin and

skirt areas.

4. Inspect each piston for seizure marks or scuffing.

Repair with #400 grit wet-or-dry sandpaper and

water or honing oil.

AN135

! CAUTION

Water or parts-cleaning solvent must be used in
conjunction with the wet-or-dry sandpaper or dam-
age to the sealing surface may result.

! CAUTION

Water or parts-cleaning solvent must be used in
conjunction with the wet-or-dry sandpaper or dam-
age to the sealing surface may result.

! CAUTION

Improper cleaning of the ring-grooves by the use of
the wrong type of ring-groove cleaner will result in
severe damage to the piston.

2-8

„NOTE: If scuffing or seizure marks are too deep
to correct with the sandpaper, it will be necessary
to replace the piston.

5. Inspect the perimeter of each piston for signs of

excessive “blowby.” Excessive “blowby” indicates

worn piston rings or an out-of-round cylinder.

„NOTE: If synthetic oil is being used, a certain
amount of “blowby” may be visible under normal
use.

CRANKCASE

1. Wash the crankcase halves in parts-cleaning sol-

vent.

„NOTE: Before washing the crankcase halves,
make sure the five bearing dowel pins have been
removed and accounted for.

2. Inspect the crankcase halves for scoring, pitting,

scuffing, or any imperfections in the casting.

3. Inspect all threaded areas for damaged or stripped

threads.

4. Inspect the bearing areas for cracks or excessive

bearing movement. If evidence of excessive bear-

ing movement is noted, the crankcase must be

replaced.

5. Inspect the bearing dowel pins for wear.

6. Inspect the sealing surfaces of the crankcase

halves for trueness by placing each crankcase half

on the surface plate covered with #400 grit wet-or-

dry sandpaper. Using light pressure, move each

half in a figure eight motion. Inspect the sealing

surfaces for any indication of high spots. A high

spot can be noted by a bright metallic finish. Cor-

rect any high spots by continuing to move the half

in a figure eight motion until a uniform bright

metallic finish is attained.

„NOTE: Care must be taken not to remove an
excessive amount of aluminum, or the crankcase
will have to be replaced. If excessive aluminum is
removed, too much pre-load will be exerted on the
crankshaft bearings when assembled.

A519

INTAKE MANIFOLD INSULATORS 

1. Inspect for cracks, scoring, pitting, imperfections,

or warping.

2. Inspect the sealing surfaces for trueness by placing

each on the surface plate covered with #400 grit

wet-or-dry sandpaper. Using light pressure, move

both sides in a figure eight motion. Inspect the

sealing surface for any indication of high spots or

warping. Correct high spots by continuing to move

each side in a figure eight motion. Warped compo-

nents must be replaced.

A932

CRANKSHAFT

„NOTE: If any servicing of the connecting rods,
center bearings, or oil-injection pump drive gear is
necessary, Arctic Cat recommends that the crank-
shaft be taken to a qualified machine shop for that
service.

1. Wash the crankshaft with bearings in parts-clean-

ing solvent.

2. Inspect the bearings for wear, scoring, scuffing,

damage, or discoloration. Rotate the bearings.

Bearings must rotate freely and must not bind or

feel rough. If any abnormal condition is noted,

replace the bearing.

! CAUTION

Water or parts-cleaning solvent must be used in
conjunction with the wet-or-dry sandpaper or dam-
age to the sealing surface may result.

! CAUTION

Water or parts-cleaning solvent must be used in
conjunction with the wet-or-dry sandpaper or dam-
age to the sealing surfaces may result.