Engine oil in Air filter housing

Hi,

I found a thin layer of engine oil in the air filter housing of my Suzuki
Maruader GZ125 when I removed the air filter for cleaning.

The bike still function normally.

Can anyone advice what has been leaking and its implication?


Thanks in advance.

 

The engine sucks fumes out of the crankcase through an oil/air
separator called a "demister". The demister is usually a square part of
the valve cover. There is a wire mesh screen inside the demister that
is supposed to remain cooler than the oil fumes, so the oil normally
condenses on the wire screen and drips back into the space underneath
and drains back to the crankcase...

If the engine gets too hot, the demister won't work, oil fumes will
condense in the air box instead, so you will always have some oil
condensing in the air box after a long hard ride...

Some motorcycles have a short rubber hose coming out of the bottom of
the airbox. The hose is like an appendix. The bottom end of the hose
has no outlet. The owner is supposed to remove the hose and
drain it when it gets full. But the owner's manual often never says
anything about this. So, when the hose becomes full of condensed oil
fumes, the incoming fumes have nowhere to condense except on the inside
of the airbox...

But, if there is a lot of oil in the air box, remove the oil filler cap
and sniff for gasoline fumes. Another clue that there is gasoline in
your oil is that the oil level in the sight glass seems to rise. This
occurs when the float valve in the carburetor sticks and the float bowl
overflows and gasoline runs down the inlet passage into the cylinder,
passes the piston rings and enters the crankcase...

Oil diluted with gasoline cannot do its job to lubricate the cylinder
wall and the bearings. Worse than that, there is the posssibility that
a spark could set off a crankcase explosion that would wreck your
engine...

 

Everything Krusty said . . . and is is possible that you just
overfilled it at some point? If overfilled, it can start blowing some
oil into the filter housing.

 

As it turned out, he seems to have be over-oiling a K&N fabric and mesh
filter and it was dripping in the air box...

 

Gotta love those simple solutions.