Problems timing my CB77
Problems timing my CB77Hi
Tried to time my CB77 but if I set up the RH cylinder the points gap to time the LH was out of spec. My thinking was that maybe the valve timing was out so I took off the head cover to check it was not off a tooth on the cam sprocket ..... but I can not see the punch mark mentioned in the manual or the line on the head to align it with. The only marks are what looks like on O or a zero and a D on the sprocket. You may be able to see on the picture. So question is how do I check the valve timing? Thanks Greg
No, you are not understanding. The 0 (zero) is the punch mark or indexing mark on the cam sprocket. There are 2 flat spots on the cam sprocket, 180 degrees from each other. Align the flat plane of the cam sprocket that has the punch mark with the flat plane of the top of the head (gasket surface) while the right piston is at TDC with the "T" on the rotor aligning with the pointer and the slash or hash mark on the points cam pointing up at 12 o'clock relative to the aforementioned plane. HT The sprocket has been welded up at some time owing to the rivets becoming slack. This may also indicate that the advancer mechanism is not in the best of shape.
The marks are clearly visible in your picture. G '60 C77 '60 C72 '62 C72 Dream '63 CL72
'61 CB72 '64 CB77 '65 CB160 '66 Matchless 350 '67 CL77 '67 S90 '77 CB400F
When I checked the flat on the cam sprocket did not seem to be exactly parallel but was definitely better than if I had moved the chain a tooth, so I have tried timing again to make sure I had not messed up but I still can not get it spot on without having one set of points out of spec, not massively so (about 0.45mm) but still can not see why unless the points cam is worn?
In practice will a larger points gap matter? Greg
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