Crankcase Oil Strainer Inspection; Engine Assembly; Crankcase Assembly; Piston Ring Installation - Polaris PREDATOR 50 2009 Manual

ENGINE / TRANSMISSION

Crankcase Oil Strainer Inspection

1. Remove strainer plug.
2. Remove oil strainer and visually inspect for any rips, tears
or obstructions in screen.
3. Replace oil strainer if it fails visual inspection.

ENGINE ASSEMBLY

Crankcase Assembly

Lubricate all bearings with clean engine oil before assembly.
1. Support left side crankcase upright.
2. Drop cam chain into position in the cam chain area and
hold.
3. Install crankshaft. Be sure camshaft chain is engaged on
lower drive sprocket.
4. Clean mating surfaces of crankcases and install alignment
pins and a new gasket.
3.28
5. Install case screws. Torque in two steps to specification
following sequence shown.
4
1
3
Crankcase Screw Torque:
87 in. lbs. (10 Nm)

Piston Ring Installation

NOTE: Apply clean engine oil to all ring surfaces
and ring lands. Always check piston ring installed
gap before rings are installed on piston. If the piston
has been in service, clean any accumulated carbon
from the ring grooves and oil control ring holes.
1. Place oil control ring expander in oil ring groove with end
gap facing forward. The expander has no up or down. The
ends should butt squarely together and must not overlap.
2. Install oil ring top rail with end gap at least 30
end of the expander.
3. Install bottom rail with gap at least 30
expander on the side opposite the top rail gap.
4. Install the second ring with the mark facing up. Position the
end gap toward the rear (intake) side of the piston.
Top
Ring Profile
Second
Ring Profile
5. Install the top ring with the chamfered edge facing up.
6. Check to make sure the rings rotate freely in the groove
when compressed by hand.
2
6
5
°
from the
°
from the end of the
Install chamfer up