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85 gl1200 timing cams without a cover

Posted: Sat Jul 17, 2021 3:37 pm
by vgj
Hiall im working on this bike for a older gentlmen.He has just got this and its been modified(rather poorly)the previous owner has left the cam belt covers off.It does not run on 1+3 even if i dribble gas down the carb,nothing not even a backfire.I also found out 1+3 plugs are siezed in the head but 2+4 come out easy,probably because it has a sidecar on it.to much trouble to work on for someone i guess.So how could I check cam timing without any covers if possible,I am thinking a degree wheel might be an option somehow.I know the plugs will have to be adressed but wanted to check cams first.2+4 plugs are good tho.thanks for any help.

Re: 85 gl1200 timing cams without a cover

Posted: Sat Jul 17, 2021 6:38 pm
by vgj
Just to add for info strong spark on 1+3, pulled 2+4 plugs and turned over buy hand,I can feel good comp. and hear slight leaking buy the rings on 1+3 with valve covers off.I have to verify cam timing and mark it if I have to pull the right head anyways.It does start and run on 2+4.Thats why I think it might be cam timing even tho the plugs on 1+3 might not be in good shape.

Re: 85 gl1200 timing cams without a cover

Posted: Sun Jul 18, 2021 7:13 am
by Andy Cote
Welcome to the forum.

If memory serves me, on the GL1200 there are cam timing marks on the pulleys and the castings. The electronic ignition timing is managed by a trigger wheel behind the crankshaft pulley. If the wheel was out of time, it would affect all cylinders Could be the pulse generator. Obviously, getting the spark plugs out is the first task.

Re: 85 gl1200 timing cams without a cover

Posted: Sun Jul 18, 2021 1:04 pm
by vgj
Thanks for replying Andy,I tried a coulpe of dial indicaters on on it to check overlap on ex valves to see if it matched on opposing cylinders on the right side, seemed to be out one tooth.I moved the cam but no luck,I think your right.I"ll see what he wants to spend. Thanks again.

Re: 85 gl1200 timing cams without a cover

Posted: Mon Jul 19, 2021 6:33 am
by Andy Cote
Ii should still run even if it was one tooth off.

I think the same module fires both cylinders on one side and I think each plug wire fires on every revolution (wasted spark on exhaust stroke). Hopefully you can get those plugs out without further disassembly.