Topic: Fuel out breather tube

[tmart]

Hey everybody,new question here about old problem.On my wifes 350f,the blow by i thought was oil blowby at idle when hot turns out to be fuel.After a ride this morning of about 20 miles,i notice a little smoke out of the breather tube,it wasn't really smoke because it did not linger like oil smoke would,more of a vapor,anyway I touch the end of the hose and a residue or maybe a drip of fuel was on my finger.I checked the oil,there does not seem to be any fuel in the oil.I know the specs on the fuel mixture screw is 7/8 turn out,mine are about 1and a half out,could this be the probelm?This little bike runs great,no black smoke out the pipes ever.Any suggestions?

thanks 
Terry

[TwoTired]

Both oil and fuel have hydrocarbons in them.

The breather vents piston ring blowby, oil vapors, and crankcase condensate contaminated with these hydrocarbons (smells like fuel).

Only when the engine and trans has been at operating temp for a certain duration of time will the steam vapor stop exiting the breather. You have to give the heat time to vaporize all the condensate inside the engine and transmission case.  This is related to outside temps.  As this is an air cooled (uncontrolled) engine, cooler outside temp need a longer time to thoroughly heat the engine unit and boil off the water inside (formed during a cool down from the humidity in the air).

20 miles is not likely long enough to do this, unless it is pretty hot out, or you are working the engine pretty hard so it develops maximum heat.  You'll need about 15-20 minutes at full operating temp to ensure water boil off.  IF it is still spewing vapor after that, then I'd check compression for ring seal issues.

Cheers,

[tmart]

Thanks two tired,I am not going to worry about it.It was about 60 degrees this morning and my wife rarely gets over 45 miles per hour.This is tough on me and my '77 wing because i hardley ever get to go in high gear.But i am not going to rush her,she just got her permit.
thanks
Terry