6.28
ENGINE
340/550 ENGINE DISASSEMBLY
NOTE: Inspect all parts for wear or damage during
disassembly. Replace all seals, o-rings, and gaskets
with Genuine Pure Polaris parts during assembly.
Refer to the ‘INSPECTONS” on page 3.5 for general
inspection procedures.
1. Disconnect the coil pack from the recoil cover and the
wiring harness.
2. Loosen the carburetor clamps (1) and remove the
carburetors from the mounting boots.
3. Note where the oil lines are routed and remove the oil lines
from the carburetors.
4. Remove the carburetor mounting boots (2) from the
cylinders.
5. Remove both the cylinder head (3) and the exhaust side
fan (4) shrouds from the engine assembly.
6. After removing the fan shrouds, take note of the vibration
dampener (5) located between the cylinders month intake
side.
7. Remove the CDI from the flywheel cover.
8. Remove the flywheel cover (6).
9. Remove the recoil cup (7).
10. Hold the flywheel with the holding wrench PN 8700229
and remove the flywheel nut and washer.
11. Using a flywheel puller (PN 2871043), remove the
flywheel (8) from the engine. Do not install the puller bolts
in amy more than 5/16” of an inch/7.9mm into the
flywheel threads or stator damage may result.
12. Remove the flywheel and woodruff key.
13. Remove the stator plate.
14. Remove the oil pump (9). Note the o-ring and shim
placement.
15. Remove the cylinder head bolts (10).
16. Remove the cylinder head (11).
17. Remove the head gasket (12). During the removal process
note that the gasket has a EX for exhaust side and UP for
the orientation.
18. Remove the cylinder base nuts (13) and carefully remove
each cylinder.
19. Remove the reed valve assembly (14) from the crankcase.
20. Remove the wrist pin c-clips
21. Using a piston pin puller (PN 2870386) remove the wrist
pins from the pistons.
22. Turn the crankcase over and remove the crankcase bolts
(15).
23. Carefully turn the case back over and separate the case
halves.
24. Remove the crankcase seals (16).
25. Remove the oil pump bushing, spacer, and cross shaft (17)
and inspect for any wear or damage.
340/550 ENGINE ASSEMBLY
1. Insert the oil pump cross shaft, spacer and bushing.
2. Install a new o-ring on the oil pump.
3. Place the oil pump aside for later installation.
4. Set the crankshaft into the lower case half.
NOTE: Make sure that the crankshaft rotates
smoothly and does not bind. Rotate the bearings so
that the anti-rotation pins are testing in their
appropriate galleries.
5. Apply 3-Bond (PN 2871557) sealer to the top half of the
crankcase.
6. Apply Polaris 2-Stroke engine oil to the oil pump cross
shaft in the lower half of the crankcase.
7. Install new crankcase oil seals.
8. Match up the top half of the crankcase to the lower case
and hold the case halves together and turn it upside down.
9. Install the crankcase bolts and torque to 18 ft-lb (25Nm).
in the pattern shown below.
10. Turn the crankcase over an install the pistons with the
arrow on the piston crown facing the flywheel (MAG)
side. This will orientate the piston so that the piston ring
locating pins will be in the intake side of the engine.
11. Apply Polaris 2-Stroke engine oil to the wrist pins and the
small end bearings and install them onto the crankshaft
with the piston installation tool (PN 2830386).
12. Lubricate rings and the pistons with Polaris 2-Stroke oil
and install the rings with the letter, mark or beveled side
facing upward.
13. Install the c-clips into the piston so that the opening of the
“C” is positioned at the 12:00 or 6:00 position.
14. Install the reed valves in to the intake of the crankcase.
15. Install new base gaskets.
16. Compress the piston rings and install each cylinder onto
the crankcase.
5
9
1
12
8
4
3
2
7
6
11
12
CRANKCASE TORQUE PATTERN-FUJI
To Next Page
Loading...
Need help?
General
