81 GS850G Gas in engine

[Kbray0009]

Hello!

I bought this low mileage bike last year for a guy who had it sitting for 15 or so years. It looks to be in pretty good shape, all things considered. Or course, the tank is empty and a little rusty.

So after having carbs rebuilt, rebuilding the brakes, and getting tires on it, I get around to changing the fluids. The engine oil was a mixture of gas and oil, which kinda makes sense and I'm not too worried. But then I change the secondary gear oil and it also has gas in it. Now I'm a little worried. I imagine there is an oil seal somewhere that is leaking? Is it only gas that can make it past this seal, or is it going to be completely toast? What else could the gas have done?

Thanks,
-Kevin

[chris]

Hi ,most common cause of gas in engine oil is vacuum petcock failure. There must be zero flow of fuel when petcock is in the on position and engine not running. I use a pingle manual petcock. Hopefully the shaft drive owners can chime in about how your engine oil could mix with your gear oil, probably a seal.

[Kbray0009]

Thanks, that's what I figured, too. I got a new petcock instead of rebuilding the old one. Now if I could just remember how to route the vent hose...

[bwringer]

Yup, it's the petcock. Very common.

When the engine is full of oil/gas, it is possible for the mix to push through the seal separating the engine and gear oil.

Personally, I would just run it and keep an eye on things. It'll probably be fine. Without that large volume of very thinned-out oil pushing, it shouldn't leak through.

[gustovh]

Grease your splines in the pumpkin, check the nut at the tranny universal.

V

[Grimly]

Grease your splines in the pumpkin, check the nut at the tranny universal.

V

That's like a line from a Lonely Planet Guide.

[fastbysuzuki]

Gas in the transmission looks like a seal has failed, Are you getting a rise in the oil level in the transmission?