Do air and oil mix

[the celt]

Might seem a strange question, but i was cleaning my 96 r1100gs the other day and noticed after taking out the air box drainage plug(found nearside rear of air box) a small amount of oil coming out maybe 100ml. I can,t find where this is coming from is it normal, any help accepted with thanks.

 

[boxer]

Could it be you've over filled it? Does the engine breather terminate in the airbox?

If it was that abnormal would there be a drain hole there anyway?

 

[notadrop]

.........agree with boxer, probable cause is overfill of engine oil - can end up in the air filter box.

 

[Deadskin]

Celt
Whats the milage ?

 

[Deryck Bowler]

I was reading a print of the R1100GS pages this weekend and remembered it mentioning that it this could be the cause, have a look at this .

 

[Paul Young]

One thing to remember is that the boxer engine is very different from an inline four which has two pistons rising as the other two fall in their cylinders. The boxer has both pistons moving outwards/inwards at the same time so the crankcase volume (behind the pistons) increases then decreases by 1150cc every stroke. This creates pressure which has to be vented somewhere and the air which comes out has oil vapour trapped in it from all the churning around inside. The crankcase volume of an inline four remains fairly constant. Try taking the oil fill cap off with the engine running....A friend of mine did this and scared himself, thinking he had blown a head gasket.

HTH,

 

[the celt]

Thanks to everyone , I think I've over filled with oil, but 50,000 on the clock and still as sweet as a nut, a big thanks to Deryck Bowler a great link to other site