GS650G Katana rebuild - firing on 3 cylinders - driving me crazy!!!!!

[IanW]

Good point, I will try your suggestion.
I sort of had an idea that it might have been something to do with the valve collets not being installed correctly and somehow jamming the valve, I never thought about a sticky bucket. It would be soooo much better not to have to remove the head. Living in South Africa, spares are not always as easily available as in other parts so getting a new head gasket is not a trivial exercise. My buddy the diesel mechanic thinks I might get away with the old head gasket as the bike has never been run. Anyone with experience with this?

[2BRacing]

Even if it turns out to be the collets causing the problem, you can rather just remove the cam with the head still on the bike. Feed some nylon rope ("ski-rope") into the plug hole, and turn the crank via the 19mm bolt on right side of crank so that the nylon rope keeps the valve from dropping into the cylinder if you remove the collets. After removing the bucket, you can inspect the retainer/collets to see if that is the problem. You should be able to push down on the retainer and remove the collets if needed.

I would really try everything before removing the head as a last resort!

[jdvorchak]

You may find that the shim was not installed correctly and just simply jumped out of the bucket! It's about time you got lucky.