Mercruiser bravo II lower unit reservoir overfilling

[Boat290scr]

I have a dual drive mercruiser 4.3L with bravo II outdrives. On my first outing of the season the port side lower unit reservoir overspilled. Something that has not happened before. Afters topping and wipping the excess oil from the area, I took the boat out again and that engine experience oscillating RPM readings. Does anyone have an idea what could be happening??

 

[TilliamWe]

Re: Mercruiser bravo II lower unit reservoir overfilling

You could have water intrusion int eh outdrive forcing the oil out the bottle. the drive could be building excess pressure forcing the oil out. I think that's possible before blowing a seal in the drive?
I had a friend that constantly had oil coming out his reservoir bottle in his boat for a summer. Later that summer he had a replacement drive on the boat. No one ever told me exactly what was wrong with his drive, though.