82 GS1100 GLZ

[Graham]

Hi Guys, I wonder if anyone can help. Way back in the summer (I bought a GS1100 in several dozen cardboard boxes. It had been completely stripped by it's previous owner who had made a start on a rebuild. I've now got the beast back together, but I have a suspicion that the exhaust valves are just touching the piston crowns at TDC. (The pistons show a slight marking and it's noisy on tickover and above). Does anyone know what the valve to piston clearance should be? and what would cause the 2 to make friends like this. It has been rebored (1mm) and I wouldn't be surprised if the head has been skimmed as well although I can't confirm it. Any body got any solutions, also I would love to confirm that they are touching at TDC does anyone know a good way of telling apart from liberal doses of engineering blue? Thanks, Graham,

[duaneage]

I woulddouble check the timing since there should be about .100 of clearance there. The head could not be shaved that much, more likely a timing problem with the cam chain.

[Graham]

The timing was seriously out the first time I put it together (duh! Forgot to take up the slack!) Which I suspect may have caused the initial marks on the piston crowns. But it's still very noisy (although possibly better than before ) It's the first time I've worked on these engines are they known for top end rattle?

[duaneage]

If it spins without contacting anything do a compression test. Ifthe valves are out of time he compression will be low. Compression tests are also used to degree dial in camshafts as well.

You should see 140 or better.

[Graham]

Hi, Thanks for that, that's a damn fine idea. I can crank it by hand without it sounding like it's hitting anything. I'll check the compression tonight and get back to you.