Re: 1978 Merc black max 150hp water in lower unit oil... am I in trouble?
Well it can be a quick fix sometimes. Some seals you can do especially if your doing the water pump at the same time. Other seals require special tools to disassemble the L/U and install.
The quick areas that can be fixed is the
1)fill/drain plugs , gaskets/seals (You would be surprised how much water can get in there)
2)The bottom housing of the water pump has Gaskets ,Orings and seal that keeps the oil/water from mixing.
http://www.crowleymarine.com/mercury-outboard/parts/490_20.cfm
Check the seals and other parts out...Some will be included in a FULL water pump kit. Some you might have to buy separate.
14 Gasket
15 Oring
17 Seal
18 Seal
Now what I meant by quick was the top seals above I mentioned are easier spots that the average person can do. Now the other seals that can go wrong require you to disassemble the L/U completely to remove and install. Those would be more time/money/tools.
To test the harder seals...
You can leave the top plug in and use a fitting on the lower plug that you use to fill the L/U up with oil and attach that to a bike pump or some other small pump. Pump it up ALITTLE bit not alot is needed. Then you can check with soapy water around the seals to check them. Can also leave the L/U pressurized overnight and see if the gauge drops over time too.
DamianJP
