Remove the spark plugs (page 3-6).
Remove the spark plug sleeve on the cam chain side using the holder attachment.
Tool: Holder attachment 07930-KA50100.
Front cylinder:
Remove the front cylinder head cover (page 8-3).
Rotate the crankshaft clockwise and align the "FT" mark on the primary drive gear with the index mark on the right crankcase cover.
Check that the index lines on the front cylinder camshaft are flush with the cylinder head surface and "F" and "R" marks facing as shown (TDC).
Rear cylinder:
Remove the rear cylinder head cover (page 8-3).
Rotate the crankshaft clockwise and align the "RT" mark on the primary drive gear with the index mark on the right crankcase cover.
Check that the index lines on the rear cylinder camshaft is flush with the cylinder head surface and "F" and "R" marks facing as shown (TDC).
Before releasing the cam chain tensioner, measure the distance the cam chain tensioner projects above the bracket as shown.
Replace the cam chain with a new one if the projection exceeds 9.0 mm (0.35 in).
To replace the cam chain, remove the following parts:
- Cam sprocket (page 8-21)
- Front cylinder: flywheel (section 18)
- Rear cylinder: primary drive gear (section 10)
Release the tensioner by pulling wedge A straight up while holding wedge B down then secure wedge A with a 2 mm pin as shown.
If you plan to replace the camshaft and/or cam sprocket, remove the cam sprocket bolts as follow:
- Remove the cam sprocket bolt.
- Rotate the crankshaft clockwise one turn (360°) and remove the other cam sprocket bolt.
- Remove the cam sprocket from the camshaft flange surface.
Be careful not to let the cam sprocket bolts fall into the crankcase.
Remove the camshaft holder bolts and camshaft holder assembly.
Remove the dowel pins.
Remove the camshaft.
Attach a piece of wire to the cam chain to prevent it from falling into the crankcase and remove the cam sprocket from the cam chain.