Flammable Goo from the Engine vent

[LeeGS550E]

Got back from a quick ride just now, and noticed yellowish goo trickling out of my air box. Started to pull the box and discovered the source of the goo is from the vent tube that comes off the top of the head and attaches to the airbox. It smelled sort of like gas, so I dripped some on a rag and sure enough...its flammable. Not quite as flammable as pure gas, and it seems to have water and oil in it. I have not changed the oil in a few hundred miles, and have been screwing with the carbs including the float bowl levels, so I won't rule out a bit of fuel in the oil, but didn't think it was that much. I've noticed others talking about the goo that comes from this vent on other models. Just wondering if this condition is normal...I'm guessing not.8-[

Guess its time to pull the header and change the oil.:?

[chef1366]

Check valve clearance. How is the compression?

[LeeGS550E]

Compression's good. All high 140's +/-. I have wondered about any potential blow-by with this engine, but I don't see that being the case with those numbers. I don't recall looking last time I had the head cover off...what portion of the engine does this vent apply to...head only, or crankcase?

Since I posted this question, I changed the oil, and found it to be a bit thin, even considering it was hot from running. Perhaps more fuel leaked in from the carbs than I thought. While tweaking with the carbs, I have had a few instances of fuel flowing into the airbox. Its fixed now, but that may have spiked my oil with more fuel than I realized. I'll run it this week on the fresh oil and see how it behaves.

[chef1366]

It's called a crankcase breather. It relieves pressure built up in the crank case like a pc valve on a car. If you didn't have one you'd blow out your gaskets.
There is two ways gas can get into this. One-through the combustion chamber which would lead me to think valve clearance or valve guides but with your compression numbers I doubt that.
Two-fuel in your oil. Petcock or float needle and seat and even fuel T o-rings in combination with a bad petcock.

Take off the breather cover and clean the wire mesh mass thingy which is supposed to keep oil out of the breather tube and airbox.

[LeeGS550E]

Take off the breather cover and clean the wire mesh mass thingy which is supposed to keep oil out of the breather tube and airbox.

Thanks chef, will do.

[gremlin]

remove the cover and spray it down with carb cleaner. the goo is oil, water and gas fumes mixed. at one time your motor had condensation and its been clogging the vent and tube.

smell your oil and see if it smells heavy of gas. if so you have a leaking carb. probably during hot weather. the gas expands and goens in th the cylinder and drips down.