Gear case leak

[Pan Fisher]

I have a 1985 25hp tiller motor. I noticed after a short hop at the lake a small oil leak coming from a small hole left of the vent plug. I have not opened the gear case yet. Any clues what would cause this?

[Solarman]

I have a 1985 25hp tiller motor. I noticed after a short hop at the lake a small oil leak coming from a small hole left of the vent plug. I have not opened the gear case yet. Any clues what would cause this?

First off, what small hole left of what vent plug? I don't know of any vent plug? Are you talking about the screw plug for the gear case oil? That plug might be labeled a vent plug?
If that's the plug, the small holes are just cavity holes for draining trapped water.
If oil is coming from there, what color is the oil?

Post back when able.

[Pan Fisher]

Gear Case Leak

This is on the right side of the gear case. According to Marine Engine. Com parts list, the top screw is a vent plug. The drain of course is at the bottom. The small hole is about 1 1/2 inches to the left of the top screw. About an eighth of an inch in diameter. The color is mostly clear, but there is some black to it.

[Solarman]

Sounds like it is 2 stroke oil from the exhaust (burnt from running) that collected in one of those cavities during running, and leaked out the weep hole for that cavity. Sounds normal from this point. Next time you replace impeller, see where the weep hole goes to. That should answer most of your questions. I'm guessing it is in the exhaust passage.

Good luck.