Polaris 2007 Sportsman 450 EFI, Service Manual

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3.8
ENGINE
RECOMMENDED COOLANT
Use only high quality antifreeze/coolant mixed with distilled
water in a 50/50 or 60/40 ratio, depending on freeze protection
required in your area..
Accessible Components
The following components can be serviced or removed with the
engine installed in the frame:
• Flywheel
• Alternator/Stator
• Starter Motor/Starter Drive
• Cylinder Head
• Cylinder
• Piston/RIngs
• Camshaft
• Rocker Arms
• Cam Chain and Sprockets
• Water Pump / Water Pump Mechanical Seal*
The following components require engine removal for
service:
• Oil pump / Oil Pump Drive Gear
• Counterbalance Shaft or Bearing(s)
• Connecting Rod
• Crankshaft
• Crankshaft Main Bearings
• Crankcase
* It may be necessary to loosen engine mounts and move
engine slightly to access water pump. Use the Water
Pump Mechanical Seal Puller ( PN 2872105 ) to replace
mechanical seal with engine in frame.
Engine Removal (TYPICAL)
1. Clean work area.
2. Thoroughly clean the ATV engine and chassis.
3. Disconnect battery negative(-) cable.
4. Remove the following parts as required.
• Seat
• Left and Right Side Covers (Refer to Chapter 5)
• Fuel Tank Cover / Front Cab (Refer to Chapter 5)
• Fuel Tank (Refer to Chapter 4)
5. Disconnect spark plug high tension lead.
6. Remove springs from exhaust pipe and remove pipe.
7. Drain coolant and engine oil.
8. Remove air pre-cleaner and duct.
9. Remove airbox.
10. Remove carburetor. Insert a shop towel into the carburetor
flange to prevent dirt from entering the intake port.
11. Remove center chain guard on chain drive AWD models.
12. Remove center drive and driven sprocket bolts and remove
chain and sprockets as an assembly.
13. Refer to PVT System to remove outer clutch cover, drive
belt, drive clutch, driven clutch, and inner cover.
14. Starter motor. Note ground cable location. Mark positive
(+) cable mounting angle and remove cable.
15. Remove transmission linkage rod(s) from gear selector and
secure out of the way.
16. Disconnect coolant temperature sensor wire.
17. Remove engine to chassis ground cable.
18. Remove all engine mount nuts and / or engine mount plates.
19. Remove engine through right side of frame.
CAUTION
Using tap water in the cooling system will lead to a
buildup of deposits which may restrict coolant flow
and reduce heat dissipation, resulting in possible
engine damage. Polaris Premium 60/40 Antifreeze/
Coolant is recommended for use in all cooling
systems, and comes pre-mixed, ready to use.