Polaris R09VA17AA, Service Manual

Page: 84 / 187

3.40
ENGINE
Camshaft Timing
IMPORTANT CAMSHAFT TIMING NOTE: In order to time the camshaft to the crankshaft, the piston must be precisely located
at Top Dead Center (TDC). This can be accomplished using one of two methods.
1. Install the cam chain over the crankshaft.
When the stator housing is removed , use Method 1. This method uses the camshaft gear marks and the crankshaft keyway to establish
TDC (see Method 1 illustration). It is important to note that this method can only be used when the stator housing is removed and
the crankshaft keyway is in view. The camshaft sprocket alignment marks are parallel to the gasket surface, and camshaft lobes are
pointing down. Cam chain plate links are not used to time the camshaft.
When the stator housing is installed , use Method 2. This method establishes Top Dead Center (TDC) by aligning the single mark
on the flywheel in the timing inspection hole (see Method 2 illustration). The camshaft sprocket alignment marks are parallel to the
gasket surface, and camshaft lobes are pointing down. Cam chain plate links are not used to time the camshaft.
Camshaft Installation - Timing Method 1
Reference Illustration Page 3.41
Stator housing is removed . NOTE: Use this method only when the stator is removed and cam shaft drive sprocket is in view.
1. Rotate the crankshaft until the keyway on the crankshaft is pointed ’UP” (keyway facing upward) and the piston is at TDC.
2. Align the cam chain onto the teeth of the crankshaft sprocket. Use a wire to pull the chain up through the cylinder and cylinder
head and to hold it in place.
Secure and maintain tension so that the chain does not fall off the crankshaft sprocket.
3. Apply engine assembly lubricant to the camshaft main journals and cam lobes. Lubricate automatic compression release
mechanism with clean engine oil.
4. Orientate the camshaft for installation with the lobes facing downward .
5. Disconnect the wire securing the cam chain and loop the cam chain over the camshaft sprocket while verifying the cam is inserted
with the alignment marks parallel to the gasket surface.
6. Verify all cam timing marks to verify proper cam timing, and install the rocker arm assembly (see Method 1 illustration). Torque
the cylinder stud nuts to specification.
NOTE: Do not rotate engine until rocker assembly and tensioner are installed.
7. Install the tensioner. Torque fasteners to specification.
8. After tensioner installation, rotate engine at least two revolutions and re-check marks/timing.
CAUTION
Serious engine damage will result if the
camshaft is not properly timed to the crankshaft.
TDC
Cam Alignment
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