black oil dripping @ prop 70hp

David Greer

Petty Officer 1st Class
Joined
May 7, 2006
Messages
219
On my 1988 70 VRO: yesterday I started it on the hose--had good pressure, pissing, etc. Hard to start as is often the case and was expected but finally got it after several large clouds of exhaust smoke. Always in neutral.
Then I noticed a small trickle of black oil coming downthe skeg from where the prop joins the lower unit. My daughter had noticed the water coming out the prop was brown and when I checked the drips, it was right oily.
I'm getting ready to go pull the prop and expect to see a failure at the seal around the shaft. If so should I expect an expensive repair? I'm at the point of upgrading the motor.
Also I noticed a small amount of oil/gas in the front of the cowl, I suspect leaking out of the carb area while the motor was stored and/or tilted.
History: ran OK in March, trouble starting in April once and battery went down so gave up; charged battery and restarted. Using fresh gas from a 6 gallon tank as I am in the process of cleaning the belly tank. It has always been cantankerous starting and has had ethanol poisoning, but carbs were done last spring to fix it. I treat the gas and have a 10 m filter, but it doesn't get run all that much.
Thanks for your insight and I'll report on the prop area when I pull it.
 

ezeke

Supreme Mariner
Joined
Sep 19, 2003
Messages
12,532
Re: black oil dripping @ prop 70hp

It's normal to expect the excess engine oil to drip through the exhaust, especially when running the engine with no load and also after storage.

See: http://forums.iboats.com/showthread.php?t=207285

Storing the motor tilted is a really bad idea, the engine will only drain properly and fully if stored in the running position.
 

David Greer

Petty Officer 1st Class
Joined
May 7, 2006
Messages
219
Re: black oil dripping @ prop 70hp

thanks; having read this I think I probably just have oil; it's way too black for lower unit lube and it's not milky.
Also could be connected to some of the oil/gas up in the cowl.
You're right about storage and I always keep mine down when not in the water, but I had it tilted some for trailering.
 

kenmyfam

Supreme Mariner
Joined
Aug 10, 2006
Messages
14,385
Re: black oil dripping @ prop 70hp

Unburnt 2 stroke oil most likely.
 
Top