Leaky Gear Case or Unburned Fuel?

[midsized johnson]

I've got blue fluid at the skeg (I'm using Quicksilver Premium Gear Lube) in front of the prop. How can I easily determine if this is gear lube and not unburned fuel? I know that a test is to pressure up the case and see if it holds, I just don't have the stuff to do that. The gearcase oil at the drainplug is a little off color, but doesn't appear to have water in it (not milky). The fluid on the skeg looks clean and clear. My first thought was that it was gear case fluid, but I'm thinking it may be fuel. Any thoughts?

 

[oldboat1]

Re: Leaky Gear Case or Unburned Fuel?

Does the stuff smell like gas? There's a lot of nasty stuff that can appear on the skeg (unburned fuel mixed with carbon from inside the leg). Usually it's just normal combustion byproducts that casually get sloughed off in the lake water(!)

 

[OBJ]

Re: Leaky Gear Case or Unburned Fuel?

Black gooey stuff dripping is usually from the exhaust. Blue stuff is likely the gear lube. Pull the prop and see if you can tell if it's from the seals. Maybe you should see someone who can test the gear case. Pressure and vaccum tests would be good.

 

[jameswilson95]

Re: Leaky Gear Case or Unburned Fuel?

I just replaced all the gearcase seals in my 40 hp evinrude and did a pressure test method suggested to me by one of the gentlemen on this forum (and it worked like a charm). The guy told me to get a valve stem and using a knife wittle it down to the point that you can screw it into the fill plug hole. Apply approx 5lbs pressure using a bicycle pump. It worked just fine. Its a cheap no hastle pressure test that anyone can do.Its kinda like pulling a rabbit out of your ***.