Yamaha F150-Oil Leak?

[txtightline]

Yamaha F150 has some "oil residue" running down the lower cowling. It appears to be coming from the small gap between the upper and lower cowling.

I've checked the oil level and its the same as when I changed the oil a month or two ago so its not leaking much.

The oil "smear" has a whitish brown tint, not exactly like motor oil.

It also doesn't seem to be "leaking" when the engine isn't running....it's not accumulating.

Any ideas?

P.S. Motor seems to be running fine...possibly idling a little lower but that could be a seperate issue I suppose.

[skyranchrob]

I am willing to bet that this is just oil you spilled during your oil change. Carefully check at the bottom of the cowling. Rob

[txtightline]

Its always possible that its from when I changed the oil...no matter how careful I was.

However, I think I would have noticed the residue prior to now...the boat has been out atleast a half dozen or more times since the oil change and I haven't noticed....not saying it wasn't there.

[conehead39]

Is the oil level , high, low ,or mid to full on dip stick??.......Is it using oil??... are you adding some oil between oil changes??

[Troutman561]

The F150's have a tendency to leave this black residue on the mid-section and lower unit. I have never heard a good explanation for this, but once theory is it is just carbon buildup from the exhaust getting washed down when the boat is being run. I ran 2 of them for 550 hours and had to clean this off every other trip, as did everyone else who had them. It is nothing to worry about and since there is no change in your oil level, it almost definitely is not that.

[txtightline]

The engine isn't using oil and it's full on the dipstick...exactly like I noted when I changed the oil 2 months ago.

The engine isn't using oil.

I guess I'll just keep an eye on it and see if anything changes. Thanks for the responses.