87 Marlin with mercruiser alpha one.....dripping baby poop?

[oscardawgg]

I own a 1987 Marlin with a mercrusier alpha one. I bought it a couple of months ago and started to notice some fluid coming out of the rear plug. I am new to boats so not to sure what i am looking at here. The fluid is brown and gray in color and looks like runny baby poop. Its not alot leaking and i cant see any visible leaks on engine. Oil and antifreeze levels arent moving at all. Just not sure what the sludge is?

Any thoughts on my poopy situation?

 

[bruceb58]

Re: 87 Marlin with mercruiser alpha one.....dripping baby poop?

Sounds like you have a leak in your drive and what you are seeing is the emulsified oil leaking out of a seal in your drive. You should drain the oil out of your drive and if it looks emusified, pressure check it for leaks.

 

[fixb52s]

Re: 87 Marlin with mercruiser alpha one.....dripping baby poop?

Are you talking about the rear hull drain plug? If so, you might have an engine oil leak. It could be a leaking valve cover, oil pan gasket or a rear main seal.
My boat gets this too when I run it because the rear main seal has a minor leak. I will fix it this winter because the engine has to come out to get to it. ​

 

[JustJason]

Re: 87 Marlin with mercruiser alpha one.....dripping baby poop?

I agree with bruce... check your drive oil. When the upper yoke seal leaks it fills the bellows and works its way into the bilge.
A boat only has so many fluids.... so just check them all
1. engine oil.... all sterndrive have it
2. sterndrive oil...... duh
3. power trim/tilt..... all (except for a few in the 60's) have this
4. power steering fluid.... only if you have power steering
5. antifreeze coolant..... only if you have a freshwater cooling
and that's about it... just run down the list and see what's low. (or high and milky)

 

[oscardawgg]

Re: 87 Marlin with mercruiser alpha one.....dripping baby poop?

new update to boat. Took it out on Delta here in cali and engine starting making noise. Only thing that was different this time was a friend told me to add some stp oil treatment to engine. I guess its made for older engines? Now RPM is at 1200 at idle and boat wont go over 25 mph. Also makes loud knocking sound if not at idle. It isnt in tune with the engine so i dont think a lifter. Just really stumped and trying to get a feel on the situation before i take to a mechanic and get mauled on price.

what do you think

 

[danond]

Re: 87 Marlin with mercruiser alpha one.....dripping baby poop?

Step 1: Quit putting snake oil additives in your engine. They are worthless and cause more issues than they prevent.

 

[JustJason]

Re: 87 Marlin with mercruiser alpha one.....dripping baby poop?

Very true............

Learn how to tune it or pay to have it tuned....