Snowmobile Arctic Cat 2-Stroke (2007 year). Manual - part 16

2-50

MD0212

„NOTE: Check the reed valve on each cylinder for
cracking or fraying around the edges. Make sure
they are closing completely.

„NOTE: To inspect a reed valve assembly, remove
the two Phillips-head screws securing the reed
valve and reed valve stopper to the block; then
remove the reed valve and stopper.

MD0088

„NOTE: Apply blue Loctite #243 on the Phillips-
head screws when assembling.

„NOTE: Make sure the angled corner on the reed
valve align with the angled corner on the reed
valve stopper.

MD0213

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

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

dome of the piston.

726-306A

„NOTE: If the existing rings will not be replaced
with new rings, note the location and top side of
each ring for proper installation. When replacing
with new rings, replace as a complete set only.
When replacing rings note notches in ring ends
which correspond with locating pins in ring
grooves on intake side of the piston. This prevents
the rings from turning on the piston when assem-
bled.

MD0208

MD0272

! CAUTION

Do not over-tighten the Phillips-head screws when
installing the reed valves and reed valve stoppers.

! CAUTION

Incorrect installation of the piston rings will result in
engine damage.

2-51

2

MD0271

8. Lubricate the piston pin bearings and install them

into the connecting rods. 

9.  Install a piston pin bearing washer on each side of

the bearings with the open sides facing the bear-

ings.

„NOTE: The open sides of the piston pin bearing
washers must face the bearing.

MD0251

10. Place pistons over the connecting rods with the

arrow (or indicator dot) pointing toward the

exhaust port; then secure with an oiled piston pin.

Install piston pin circlips with the open ends up or

down.

MD0293

MD0248

11. Place the cylinder base gasket into position on the

crankcase making sure the gasket is properly ori-

ented so the dowel pins will fit through the holes

easily.

„NOTE: Be sure to spray a thin coat of Copper
Coat Gasket Sealant (p/n 0636-092) onto the gas-
ket if it is being reused.

12. Rotate each piston ring until the ring ends are

properly positioned with the pins in the ring

grooves; then apply oil to the piston assemblies

and cylinder bores. Using a ring compressor or the

fingers, compress the rings and slide the cylinder

over the piston. Seat the cylinder firmly onto the

crankcase. 

„NOTE: The cylinders should slide on easily. DO
NOT force them on.

MD0229

13. Secure each cylinder by installing the four 6 mm

and eight 10 mm nuts. Tighten the 10 mm nuts to

specifications and the 6 mm nuts to specifications.

! CAUTION

Make sure the circlips are firmly seated in their
grooves and the open ends are pointed up or down
before continuing with assembly.

2-52

MD0086

MD0087

14. Install a new cylinder head gasket and the cylinder

head; then install the eight cap screws and two

nuts with washers. Tighten in three steps to speci-

fications using the pattern shown.

MS384

MS384

0738-291

15. Install the spark plugs; then tighten to specifica-

tions. Pressure test the engine (see Section 3).

MS385

16. Position the seal retainer plate on the PTO-side;

then install the four cap screws. Tighten the cap

screws to specifications.

MD0253

MD0292

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2

17. Install the stator plate so the ignition wire cut-out

is in the upper left position. Lightly coat the four

Allen-head cap screws with red Loctite #271; then

install and tighten them to specifications.

MD0255

18. Place the stator wiring through the hole in the

crankcase; then install the stator. Lightly coat the

three Allen-head cap screws with red Loctite

#271; then tighten them to specifications.

MD0076

MD0274

19. Place the ignition timing sensor wiring through the

hole in the crankcase; then position the ignition

timing sensor and install two Phillips-head cap

screws (coated with red Loctite #271). Tighten the

cap screws securely.

MD0074

MD0073

20. Install the rubber insulator grommet into the

crankcase.

MD0262

21. Install the key; then install the flywheel and cap

screw (threads coated with red Loctite #271).

Tighten the cap screw only until snug.

„NOTE: Do not tighten the flywheel cap screw at
this point.