Fuel in crankcase?

[dbeardslee]

no compressed air through attached hoses. check

That's with the carb bowls in place. With them removed you can blow compressed air through the lines with no problem.

[puskrat]

very well put beardslee. It was actually an Iowan, believe it or not, who coined the ethanol is theft line. I sold cars for eight years, and in the middle of that I spent a boring day in the showroom reading through EPAs fuel mileage guide. Flexfuel vehicles get worse mileage than conventional even on E90, and the numbers work out to an increased consumption of petroleum fuel when one takes the time to do the algebra. But they told us not to worry about algebra, it won't be useful.........

Also I failed to respond to a question. I have stock pipes and stock airbox. I have toyed with some ideas, as one of the mufflers is wounded, but I want to get on the road THEN start changing things.

[puskrat]

Oh and I appear to be misusing jargon
I thought e90 was 10% ethanol...the "std" mixture

So Just look at everything I've said, do a "find" e90 and "replace" with e15.
Thank you

[dbeardslee]

I have stock pipes and stock airbox.

Then jetting should be 137.5 mains with 42.5 pilots with the '79 carbs. Trying to find the slide needles is like looking for a needle in a stack of needles, so you'll probably have to stick with what you've got. It's a good idea to take the slides apart (although you'll need some deep reach snap ring pliers to do the deed) to make sure the clips are in the middle slot and that they're properly assembled. Might check the needles for markings too - if there are any they should read 5GZ6.

[puskrat]

Originally Posted by puskrat

Oh and I appear to be misusing jargon
I thought e90 was 10% ethanol...the "std" mixture

So Just look at everything I've said, do a "find" e90 and "replace" with e15.
Thank you

Edit because more stupid:

So Just look at everything I've said, do a "find" e90 and "replace" with e10.

[puskrat]

Not exactly beating a dead horse, but how does the gasoline leaked past the float valves get from the carburetor into the crankcase? When i was describing this scenario to a Harley guy, he thought bad rings. I'm thinking not, but I know the mixture will be thinner than the oil those rings usually deal with....

[dbeardslee]

Originally Posted by puskrat

Not exactly beating a dead horse, but how does the gasoline leaked past the float valves get from the carburetor into the crankcase? When i was describing this scenario to a Harley guy, he thought bad rings. I'm thinking not, but I know the mixture will be thinner than the oil those rings usually deal with....

Some of it drips out of the airbox, and some of it goes out the other end of the carb, into the cylinder, past the rings, and into the oil. Rings don't exactly have a waterproof (or gas-proof as the case may be) seal.

[MPittma100]

Originally Posted by puskrat

Not exactly beating a dead horse, but how does the gasoline leaked past the float valves get from the carburetor into the crankcase? When i was describing this scenario to a Harley guy, he thought bad rings. I'm thinking not, but I know the mixture will be thinner than the oil those rings usually deal with....

Specifically by the ring end gaps. All engines that are in good running condition with good compression will have normal 10%-15% cylinder leakage. This leakage is what gets into the crankcase by the ring end gaps. That is why the crankcase has to have a breather. Otherwise, you blow a gasket or seal. There is such a thing as gapless piston rings, but are typically for racing.

To easily prevent crankcase flooding with fuel, simply put a 2X4 under the front wheel with bike on center stand. Leaking fuel will run into air box instead of the engine.

[HalfCentury]

My XJ650 had gas in the oil when the PO delivered it to me. Upon disassembling the carbs, I found rust particles in every nook and cranny of the carbs. The tiny rust particles can lodge between the float needles and the seats causing the gas to get by the float needles and eventually into the crankcase.

After I cleaned the carbs and re-assembled, I installed lawnmower cheapo fuel filters and never had a problem with gas getting into the oil of that bike. I ran that bike 4 years and the carbs never needed any attention during that time.

[motoman]

Originally Posted by puskrat

Sounds like a definitive solution. Thanks, Pitt. I recognize that ID from the thread I mentioned. Appreciate seeing your input. IIRC, the idea was put forth to do a prelim oil/filter change with throwaway oil and after a quick run, do it again with keeper lube.

P.O. claimed to have rebuilt carbs before storing the bike. Could they have fouled somehow while sitting?

nope........fouled up by mis-guided PO.