Looking at 81 GS750E needs airbox

[Steve]

Are you sure it's water? Could be gas diluting the oil from a leaky petcock.

At least verify proper operation of the petcock before trusting it to hold back the gas.

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[jdvorchak]

Yes I'm sure it's water... Looks like a milkshake And I already know the petcock leaks in the "on" position so I'll have to rebuild it. This is all pretty normal stuff for reviving an old barn, or in this case, back yard find. I did confirm it has spark so there is a chance it will run once I get the carbs cleaned. I'll pour a few quarts of kerosene in there and spin the starter with the spark plugs out then drain it again and see if I still have water. What ever water is left will boil out on the first run of 20 minutes or so. I am going to pick up oil and a filter in a few minutes then probably try a compression check with the new oil. I expect it to be a little low but some MMO in the cylinders will finish cleaning that out. This is not going to a fast revive. Every inch of this bike needs attention. Wires, fluids, switches etc. But that is why I bought it. I needed a project and got one.

[Steve]

And I already know the petcock leaks in the "on" position so I'll have to rebuild it.

Save your money and some aggravation, just replace it.

Seems that the overall success rate with rebuild kits is only 10-15%, after which you will have to buy a new one, anyway.

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[jdvorchak]

I agree that the success rate is small but I always end up taking them apart and seeing what's wrong then make the determination of rebuild or replace. I just rebuilt my KZ1100 and it's fine. But it had the diaphragm torn so it was an easy fix. Last Suzuki I had I couldn't get it to stop leaking so I bought a new one. Usually all it costs me is an O-ring, which I have plenty, or a new 5 hole gasket. I'm about 50/50 on rebuild success over the past dozen or so.

FYI I revive a lot of old UJM's. Gives me something fun to do. Then I usually flip them and go buy a couple more.