Polaris SPORTSMAN 400 2003, Service Manual

Page: 58 / 274

ENGINE
3.7
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. 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 and ready to
use.
COOLING SYSTEM
SPECIFICATIONS
Fan Switch (Off)
Fan Switch (On) 149 F (65 C) 8
180 F (82 C) 3
Hot Light On 221 F (105 C)
System Capacity 2.25 Quarts
Radiator Cap Relief
Pressure
13 PSI
Thermostat Starts opening 176 F
(80 C)
Open 8mm @ 205 F
(96 C)
ACCESSIBLE COMPONENTS
The following components can be serviced or
removed with the engine installed in the frame:
S Flywheel
S Alternator/Stator
S Starter Motor/Starter Drive
S
Cylinder Head
S Cylinder
S
Piston/Rings
S
Camshaft
S Rocker Arms
S Cam Chain and Sprockets
S
Water Pump / Water Pump
Mechanical Seal*
The following components require engine removal for
service:
S Oil pump / Oil Pump Drive Gear
S
Counterbalance Shaft or Bearing(s)
S Connecting Rod
S
Crankshaft
S
Crankshaft Main Bearings
S 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.
S Seat
S Left and Right Side Covers (Refer to
Chapter 5)
S Fuel Tank Cover / Front Cab (Refer to
Chapter 5)
S 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.
Enfocus Software - Customer Support