How Did This Happen?

I have a Johnson 9.9 kicker. I noticed dark brown oil coming out of the prop exhaust. Took it for repair and new prop bearings and seals were put in. This was done in October 2009. The motor was not run or started until last April (2010) when it was run for about 45 minutes a slow speed trolling. Now, when I started it last week (a year later), the same dark brown oil started coming out of the prop. Plus, there was oil leakage at the seams of the casing of the lower unit assembly.

Hummmmm, how could this happen? One guy said fishing line - well, actually, there was about 18" of line around the prop - but the front seal is fine - how could fishing line affect the rear seal?

My thought is that the shop that did the seals either didn't do the rear seal or screwed it up installing it??? 45 minutes of run time surely couldn't have done any damage to the rear seal causing the lower unit oil to leak into the prop exhaust??

Also, the oil leak at the seams tells me he didn't put in ne gaskets and/or seal them properly??

Any thoughts? Could it be a bent prop shaft or more likely a bad repair to begin with???

Check your lower unit oil and see what color it is. Be ready to drain it and replace it. If lower unit oil is coming out, water could be getting in. Don't run the engine before checking the oil so you don't mix the water, if there is any, with the oil.

Fishing line around the prop shaft will generate heat that destroys the prop shaft seal.

There's no gasket at that seam.

Exhaust will carry some oil, and if the gasket at the exhaust tuner where it joins the lower unit is bad, you'll get oil at that seam. Exhaust oil is usually black, where as lower unit oil, if it's not too old, will still be the color of the oil that's been put in, usually a brown or green, possibly have a blue tint to it, and a bit clear.

If you drain the oil and water comes out first, you need to get the lower unit pressure tested to determine what seal is leaking. Prop shaft seal or drive shaft seal under the water pump.

I believe the oil your seeing is exhaust oil. #-o

Your gearcase never needed a reseal in the first place. You are seeing unburned fuel and oil exiting exactly where it is supposed to. Prolonged idle will increase the amount some.

perhaps it is time to de-carbon the motor as well.