Engine and Transmission

Compression

Submitted by xjcdadmin on Fri, 06/18/2010 - 01:46

Insufficient compression pressure will result in performance loss and may indicate leaking valves or worn or damaged piston rings. Procedure:

1.    Make sure the valve clearance is correct.

2.    Warm up the engine 2^3 minutes.

3.    Remove all the spark plugs.

4.    Install a compression check gauge.

Camshaft, chain and sprockets

Submitted by xjcdadmin on Fri, 06/18/2010 - 01:46

1. Camshaft

a.   The cam lobe metal surface may have a blue discoloration due to excessive friction. The metal surface could also start to flake off or become pitted.

b.   If any of the above wear conditions are readily visible, the camshaft should be replaced.

Crankshaft

Submitted by xjcdadmin on Fri, 06/18/2010 - 01:46

1. Crankshaft run-out

Support the crankshaft at both ends on V-blocks. Measure the amount of crankshaft run-out on the main bearing journals with a dial gauge while rotating crankshaft.

Run-out limit: 0.03 mm (0.0012 in)

If run-out exceeds limit, replace crankshaft.

2.    Inspection of bearings

Transmission, Starter clutch and Seals

Submitted by xjcdadmin on Fri, 06/18/2010 - 01:46

Inspect each shift fork signs of galling on gear contact surfaces. Check for bending. Make sure each fork slides freely on its guide bar.

2.    Roll the guide bar across a surface place. If the bar is bent, replace.

3.    Check the shift cam grooves for signs of wear or damage. If any profile has excessive wear and/or damage, replace cam.

Cam Chain Adjustment

Submitted by xjcdadmin on Fri, 06/18/2010 - 01:46

The cam chain becomes stretched with use, resulting in improper valve timing and engine noise. To prevent this, the cam chain ten-sioner must be adjusted regularly.

1.    Remove the timing plate cover.

2.    Slowly rotate the crankshaft counterclockwise until the "C" mark on the timing plate aligns with the stationary pointer.

Crankcase

Submitted by xjcdadmin on Fri, 06/18/2010 - 01:46

Crankcase disassembly

1.    Remove the right-front crankcase cover.

2.    Remove the upper crankcase bolts, starting the highest numbered bolt.

Turn over the engine and remove the lower crankcase bolts.

CRANKCASE TIGHTENING SEQUENCE

LOWERCASE

Cylinder head and Camshafts

Submitted by xjcdadmin on Fri, 06/18/2010 - 01:46

a. Install the new cylinder head gasket. Install the dowel pins and "o-rings".

b.   Install the cylinder head onto the cylinder. Pull the cam chain through the cylinder head as it is installed. Tie the cam chain so that it does not fall into the crankcase.