Snowmobile Polaris 2006 - 2007 FS / FST. Manual - part 35

6.31

FS / FST Engine

Rev. 1 07/2006

19. Insert a pry bar between the crankcase and alternator. Pull

until the drive belt cannot be twisted more than 90 degrees
in either direction. Torque alternator pivot bolt and upper
alternator support bolt to specification listed at beginning
of chapter.

Flywheel Removal and Installation

Suspend the engine inside the engine compartment. See
“Suspending Engine” on page 5.2.

Follow the procedures for removing the MAG-side engine
support plate, removing the engine mount, remove the
pulley, and moving the alternator, found in the MAG Gear
Cover Assembly / Water Pump Driveshaft Removal and
Installation section. See “MAG Gear Cover Assembly /
Water Pump Driveshaft Removal and Installation” on
page 6.30.

NOTE:

Only the flywheel cover plate requires

removal, not the complete gear cover.

Install the flywheel puller into the flywheel, PN: PS-48041.

NOTE: Do not thread the puller screws into the
clutch rollers on the backside of the flywheel.

Slowly tighten the puller bolt while applying heat to the

flywheel outer bearing surface. Hold the crankshaft
stationary with the crankshaft arrestor. Remove the
flywheel.

Verify the flywheel locating pin is not sheared or damaged.
To remove the pin, either carefully grasp the pin with a pair
of wire cutters, or push the pin into the crankshaft bore.

NOTE: When using heat, do not dis-color the
flywheel bearing surface.

NOTE: The crankshaft locating pin is used only to
locate the flywheel position during flywheel
installation.

With the flywheel removed, inspect the following items:

• Starter clutch overrun clutch. The starter gear should

rotate freely counter-clockwise, but not rotate when
turned clockwise as viewed from the back of the
flywheel. Replace flywheel if clutch function damaged,
or motion binds when rotated counter-clockwise.

• Inspect the timing rotor teeth. Replace flywheel if teeth

are missing or damaged.

• Inspect the flywheel needle bearings. Replace if

damaged or binding.

Assembly is the reverse of disassembly. Clean the flywheel
taper with Loctite

cleaner spray.

Install the flywheel needle bearings before inserting locator
pin into crankshaft.

Coat needle bearings with engine oil.

10. Press location pin into crankshaft so that bottom of pin is

flush with the inside diameter of the crankshaft bore.

NOTE: Exposed pin height cannot exceed 17.5mm.

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FS / FST Engine

Rev. 1 07/2006

11. Apply a thin coat of Loctite 640

(GREEN) in four lines

to the inside diameter of the flywheel taper.

12. Install flywheel onto crankshaft and rotate until flywheel is

seated on the locating pin.

NOTE: When the flywheel is properly seated on the
locating pin, turning the flywheel will turn the
crankshaft.

13. Apply a thin bead of Three Bond 1215 to the front cover

mating surface.

14. Install front cover making sure cover seal lips do not fold

over.

15. Tighten fasteners to specification listed at beginning of

chapter.

16. Reinstall alternator pulley. Secure crankshaft PTO-end

with arrestor tool, and torque pulley bolt to specification
listed at beginning of chapter.

17. Install MAG engine mount / alternator assembly.

18. To tension the alternator belt, insert a pry bar between the

crankcase and alternator and pull until the drive belt cannot
be twisted more than 90 degrees in either direction. Torque
alternator pivot bolt and upper alternator support bolt to
specification listed at beginning of chapter.

High Pressure Oil Pump

Remove the engine from the engine compartment.

Remove the c-clip from the oil pump bore.

Remove the oil pump cap. Discard both o-rings.

Remove the inner and outer rotors. Inspect the rotors for
abnormal wear and tear. Replace rotors if worn.

NOTE: Dots must face the same direction.

Remove the timing rotor and drive key from the pump bore.
Verify the locking pin is in intact and that there is no
abnormal wear found on the rotor.

TIMING

DRIVE

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Inspect the drive key for damage.

Assembly is the reverse of disassembly.

Install the timing rotor, and verify the locking pin is
engaged in its designated bore.

Install the inner and outer rotors with the orientation dots
facing outwards.

10. Install two new o-rings on the pump cap.

11. Verify the snap ring chamfer faces out during installation.

Gear Train

NOTE: The following gears can be replaced without
crankcase disassembly:

• Starter Motor Pinon Gear

• Balance Shaft Drive Gear

• Water Pump Pinon Gear

• Water Pump Driveshaft / Gear Assembly

• Scavenge Oil Pump Pinon Gear

• Scavenge Pump Drive Gear

NOTE: The following gears require component
replacement and crankcase disassembly:

• Crankshaft Timing Gear - Requires crankshaft

replacement.

• Water Pump Pinon Drive Gear - Requires balance shaft

replacement.

Follow the procedures for removing the gear cover and
flywheel preceding this section in this chapter. See “MAG
Gear Cover Assembly / Water Pump Driveshaft Removal
and Installation” on page 6.30. And See “Flywheel
Removal and Installation” on page 6.31.

The starter motor pinon gear and scavenge oil pump pinon
gear can be removed by simply sliding the gears off of their
respective shafts.

Remove the balance shaft drive gear by removing the nut,
then install the gear removal tool, PN: PW-46982. Pull the
gear off of the shaft.

The water pump pinon gear can be removed once the
balance shaft drive gear is removed.

Inspect each gear as it is removed for signs of damage and
improper function. Gear bearings should rotate smoothly
without binding.

When installing the balance shaft drive gear, apply
Loctite

272 to shaft threads.

Position the gear / balance shaft so the single dot on the gear

aligns with the single dot on the crankshaft drive gear.

Torque nut to specification listed at beginning of chapter.

Reference the procedures for installing the gear cover,
flywheel and MAG engine mount to complete reassembly
procedure.

STARTER MOTOR PINION GEAR

OIL PUMP DRIVE GEAR

PINION GEAR

BALANCE SHAFT GEAR

WATER PUMP DRIVESHAFT

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FS / FST Engine

Rev. 1 07/2006

Cylinder Head / Valve Train

Remove the engine from the engine compartment.

Remove the valve cover.

Remove the exhaust manifold / turbocharger assembly.

Rotate the engine so the engine bedplate is up. Remove the
bedplate from the crankcase.

Install the crankshaft arrestor tool, PN: PS-48039, on to the
PTO shaft. Turn the engine so the cylinder head is up.

Turn the crankshaft arrestor tool in the direction of forward
engine rotation until the MAG cylinder is at TDC-
compression stroke.

NOTE: TDC-compression stroke can be identified as
when the piston is at its maximum upwards travel
and BOTH rocker arms are loose revealing that the
valves are closed.

Push the rocker arm pins out and remove the MAG rocker
arms.

Rotate the engine in the direction of forward engine rotation
until the PTO cylinder is at TDC-compression stroke.

Push the rocker arm pins out and remove the PTO rocker
arms.

10. Remove the valve shims from each valve assembly. Collect

each rocker arm, pin and valve shims as they were removed
from the engine. Place each set in a container or bag with
accurate labeling noting where each component is used
during assembly.

11. Remove the chain tensioner plug using a large pipe wrench.

NOTE: The chain tensioner plug is located on the
exhaust-side of the crankcase.

12. Attach the chain breaker tool, PN: PW-46985, to the chain.

Verify that the pressing pin (pin with detent nose) and plate
with a hole is installed in the tool before securing the tool
to the chain links.

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