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Snowmobile Polaris EDGE / WIDETRAK (2007-2012 year). Manual - part 31

5.22

Engine Systems

9923396 - 2007-2012 EDGE/Widetrak LX Service Manual

Piston and Crankshaft Assembly

Disassembly / Assembly Process

Using a small, flat-blade screwdriver, remove the c-
clips. Discard the c-clips.

Remove the piston pins using the piston pin puller, PN
2870386.

When replacing a piston, always replace the rings, c-
clips, pins and needle bearings with new parts.

Inspect the crankshaft as outlined in the Engine
Inspection section within this chapter.

Install the piston rings with the beveled edge facing

upwards.

The piston ring locator pins and ring open-ends
always face the intake-side of the engine.

Always lubricate the piston assembly and cylinder
with two-stroke engine oil when installing the cylinder
over the piston.

PISTON RINGS

PISTON

C CLIP

PISTON PIN

NEEDLE BEARING

ROD PIN

CONNECTING ROD

BEARING

THRUST WASHER

RETAINING RING

BEARING

WASHER

FLYWHEEL NUT

FLYWHEEL KEY

PTO CRANKWEB

MAG CRANKWEB

CTR CRANKWEB

CAUTION

Wear eye protection when removing or installing piston
c-clips.

Fastener

Torque

Note

Flywheel Nut

62 - 70 ft.lbs.
(83 - 95 Nm)

Flywheel and
crankshaft tapers
to be clean and
dry.

5.23

Engine Systems

9923396 - 2007-2012 EDGE/Widetrak LX Service Manual

550 FAN ENGINE

Blower Housing Assembly

Disassembly / Assembly Process

Clamp recoil rope with a pliers at the engine. Remove
recoil handle from rope, pull the rope through the
console, then tie a knot just above the pliers. Remove
the pliers.

Remove the screws that mount the upper and lower
blower housings to the engine.

Remove the recoil / fan housing from the engine. The
recoil pulley is located inside the housing.

Reference RECOIL PULLEY section for recoil
disassembly / assembly information.

The fan / flywheel and stator must be removed to

remove the rear blower housing.

UPPER BLOWER HOUSING

LOWER BLOWER HOUSING

RECOIL / FAN HOUSING

BLOWER HOUSING

RECOIL HUB

FRICTION SPRING

FRICTION PLATE

RATCHET

RATCHET SPRING

RECOIL PULLEY

RECOIL SPRING

Fastener

Torque

Note

Recoil Hub

9 ft.lbs. (12 Nm)

Friction Plate /
Recoil Pulley

5 ft.lbs. (7 Nm)

Recoil / Fan
Housings

Secure fasteners
after all covers are
in place and
snapped together.

5.24

Engine Systems

9923396 - 2007-2012 EDGE/Widetrak LX Service Manual

Cylinder Assembly

Disassembly / Assembly Process

Remove the carburetors, intake boots, exhaust
manifold, and blower housing from the engine
assembly. Discard all used gaskets.

Remove cylinder head screws. Remove cylinder
head, then discard gasket. Note the orientation of the
head for use during assembly.

Remove the cylinder base nuts. Lift the cylinder off of
the crankcase. Discard the cylinder base gasket.

Remove reed valve cage and inspect for abnormal
wear and damage. Replace reed pedal and/or cage if
damage or wear is found.

During assembly, the reed valve assembly is installed
under the cylinder base gasket. Install the base
gasket with the sealing strip facing upwards.

Lubricate cylinder walls and piston with two-stroke

engine oil when installing each cylinder.

Install head gasket with “EX” on the exhaust-side of
the engine and “UP” on the intake-side of the engine.

Verify vibration dampener is installed between
cylinders before installing blower housing covers.

CYLINDER HEAD

CYLINDER HEAD GASKET

CYLINDER

EXHAUST GASKET

VIBRATION DAMPENER

CYLINDER BASE GASKET

SCREW CLAMP

INTAKE BOOT

REED / REED CAGE
ASSEMBLY

Fastener

Torque

Note

Cylinder Base Nut

25 - 29 ft.lbs.
(34 - 40 Nm)

Cylinder Head

Screws

17 - 20 ft.lbs.
(23 - 28 Nm)

Intake Boots

5 ft.lbs. (7 Nm)

5.25

Engine Systems

9923396 - 2007-2012 EDGE/Widetrak LX Service Manual

Oil Pump Assembly

Disassembly / Assembly Process

Remove the two pump mounting screws. Pull pump
out of crankcase bore. Discard o ring.

Extract shim(s) behind pump body. Count the number
of shims and retain.

Extract bushing and inspect. Replace if abnormal
wear and tear is found.

Remove drive gear using a needle nose pliers.

Lubricate all parts with Polaris Two-Stroke engine oil
during re-assembly.

Install the exact amount of shim(s) that were removed.
Verify return spring works and applies tension to the
lever.

Follow the oil pump bleed procedure outlined in the

Maintenance chapter.

GASKET

AIR BLEED SCREW

BUSHING

O RING

SHIM WASHERS (AS REQUIRED QTY.)

OIL PUMP DRIVE GEAR

WASHER

LEVER

RETURN SPRING

Fastener

Torque

Note

Oil Pump Screws

48 - 72 in.lbs.
(5.5 - 8.3 Nm)

Oil pump is not
serviceable.

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