[johnn]

After using my 1970's 50HP Evinrude each time it drops a small amount of oil out of a small hole that looks like a vent hole just below the water intake holes on the right hand side of the motor (when looking from behind)Is this hole a vent for the gear case oil & should I replace the oil? Or is it a vent for exhaust sludge that needs to drain out? Thanks John.

[petryshyn]

Sounds like a drain hole for the water pump cavity. Engine slime can get there when the motor is tilted.>Is the gear box oil OK?>It is possible that the input shaft seal or the shifter O-ring are leaking, but the color of the oil will be the telltale. Smell it. If it smells like it came out of the butt of a skunk, you got a gear box leak. If it has that beautiful aroma of 2-stroke oil buring on a open lake, wind blowing in the girlfriend's hair, sun beating down............you're OK!!!CHECK THE GEAR OIL COLOR AND LEVEL. If there OK,......roll on!! (might want to tweak the idle mixture)

[johnn]

I had a look at the oil & it is clear & brown so no trouble there I think. It did seem to have a blackish sort of scum on top of the oil but nothing to worry about I think. I wonder where that hole/vent is connected to it must be there for a good reason, if any one knows please let me know.Thanks John.

[alcan]

Helllo johnn. These little holes are drain holes. They drain water from the unsealed area of the lower unit. Unburned fuel,oil (exhust gunk) often drain out here also.