rebuilt engine low compression top speed!! worn cam

[robbiem1961]

Hello again my mate, I know you that you've checked and rechecked the valve timing, but have you definately got the correct cam timing set up for your model, and is the 'new' secondhand cam correct for your model; has the cam chain the correct number of links
We stripped and rebuilt yamaha xs 1100 some years ago due to valve stem seals leaking, when we fitted and timed the cams we couldn't align the timing mark EXACTLY as specified, she turned by hand, but bounced all her exhaust valves when we started her
I'm asking this as i've been reading through my gs 650 clymer manual, and the valve timing is 1 tooth different different between the chain and shaft drive models: WHY? Do not ask me, i am a welder

[cornishgs]

Having fitted replacement cam,one size up main jets 82.5's,a nd a new coil took it out today and hesitation and lack of power has now gone pulls strongly and quickly up to 95mph and would have gone faster if I had wanted too.(chickened out!!--- after 30 years not riding a bike 90 seems plenty fast enough for now.

I now think it was down too a 1duff coil as I cant see as changing jetting by 1 size or the slightly worn cam would have had such an effect.If I had done it one step at a time I might have found out which bit was causing issues, or it might have been a combination of all three.things.
any way I;m well pleased with the way it runs now.


thanks for advice all