What would cause oil to get in my carburetor?

Question

I have a FXSTC Harley. The bike will run however, there is oil getting in my breather and my spark plugs are fouled. I need to know what woudl cause this and what can I do to fix it?

Answer 1

There is a rebreather tube that can allow oil to enter the intake.

Also, every bike requires a valve check at one point, I think that this may actually be your valve guides wearing down and letting oil out onto the plugs. Its a slow leak without much smoke.

First, double check that you have the right amount of oil, if you are positive that it is correct, take it to the dealer and see if they can find the problem. It can only be a rebreather valve or worn guides.

It is apsolutely not bad rings. No bike would even start with rings bad enough to do that.

Answer 2

I don't know about Harleys, but a guy brought his bike into the shop because it was blowing smoke out the exhaust like a fire extinguisher. It turned out, he did his own oil change, but forgot to drain the oil first. He over filled the crankcase by 4 quarts. The oil blew out the crankcase breather tube into his air box.
The EPA requires the crankcase breather tube go into the air box. Instead of oil accumulating on the street, it's burnt when the engine sucks it from the air box. Also at the bottom of the air box is a catch tank that collects oil and water to be drained at each service. Like I said, I don't know about Harley's. Just something to think about.

Answer 3

i think these guys answered your question. if you have too much oil in it, the oil will come out the breather into the air cleaner to be burned in the combustion chamber. it must be a lot to foul the plugs...
check the bypass and breather system, oil pump circuit and make sure there isn't too much oil in the sump. as a last resort you can unhook the hose from the air cleaner and run it into a catch can (don't drain it into the open air-the engine also "inhales" through this tube. see your dealer or other qualified motorcycle mechanic. i really doubt it is rings or valve guides, though.

Answer 4

mine did that take the stock breather off ,where the engine breather is run a tube down to the ground just don't tell anybody
went to Sturgis93 blew oil on my breather ,run the breather tube down to the ground no trouble since or after 1993 you can get different bolts that have holes through them an mount the screaming eagle back plate for your carb its legal

Answer 5

If the spark plugs are fouled with an oily residue, it's a sure sign of bad piston rings.

Answer 6

Bad piston rings.