oil seeping from lower unit after motor has run in tank

[jwilkey84]

I have been running a 20hp johnson in a tank to try and make it water worthy, and I have noticed that after I run it in a tank, black oil runs out of holes in the lower unit. I was wondering if this is normal. It is coming out of tiny holes above the water inlet for the impeller, probably about 2-3 inches above the cavitation plate on both sides. I have just been idling it in a tank and it probably has lots of carbon build up inside, if I had to guess as well.
It is very cold here in iowa today, I lifted up on my fuel line which was in the back of the pickup today outside with a temp this morning of -4, and the fuel line instantly shattered in 4 places!!!!!!! I guess now I can get a new fuel line and eliminate that as one of my possibilities on why I cant get this motor to work correctly.

 

[ezeke]

Re: oil seeping from lower unit after motor has run in tank

The oil is just unburned mix and carbon draining from the engine. With no load the oil will not be burned off. Good thermostats, yearly de-carbon treatment and 100% synthetic oils will produce less of the black stuff, but it is still normal.

The oil is particularly hard on the water pump impeller if left there for long, so it is best to flush the pump with clean water after the tank.

I understand that rubber is basically a hydrocarbon and can be either dissolved or plasticized by other hydrocarbons. I would guess that your old hoses have been plasticized. The newer fuels with alcohol are particularly damaging to old hoses which were not designed for anything but gasoline.

 

[frustratedboater]

Re: oil seeping from lower unit after motor has run in tank

WOW -4? You're a die-hard! I went goose hunting on Monday and it was 22 in Delaware--Froze my rear off, but had fun. Have you sprayed anything in/on the powerhead that may have dripped down in the exhaust in the motor? Was the motor winterized a few months prior and just seeing the reminants...? Is the fuel the correct 50:1 ratio or perhaps a little heaver oil mix? Just a few questions to isolate the possibilities.
~FB~

 

[GreatRiverDucker]

Re: oil seeping from lower unit after motor has run in tank

Sorry to highjack the thread.:redface:
Frustrated- what kind of geese? brant? canada?