A Milky Dilemma..

RobMcBee

RobMcBee

Slow n easy when you're not gettin greasy....
Joined
Jan 12, 2009
Location
Fort Mill / Indian Land SC
I've run into a bit of a snag and need some advice... I recently inherited a boat, something I've wanted for a long time. Unfortunately it had been neglected for about 5 years. Today I decided to start messing with the engine. I pulled the dipstick and its got about 6 inches of milky sludge on it... My first thoughts.... well shit... motors gone, but its been sitting on the trailer for the past 5 years, not in the water. My mom (it was her husband that passed) said it ran perfectly fine last time they used it, and he never mentioned anything wrong with it.

Could this be condensation? What are the steps I need to take to check the engine is ok without pulling it?
Im going to suck out the sludge and do a compression test. What else would yall recommend?


It's a 7.4L engine that was rebuilt approx. 15 years ago with 300 or so hrs on it.
 
Drain the oil, remove the filter, remove the plugs, fill each hole with ATF, let it sit for a few days, then try to turn it over by hand.

Might as well pull the valve covers, too... just for a look around.

I'm guessing it's an I/O?
 
I've done the atf trick on a merc350 and it was milky oil when I got to it! It smoked like hell after we drained atf and flushed with 10 gallons of cheap oil but ran no problem for a few years!!
 
Second the ATF. My concern would be if the boat was winterized when it was put up. Boat engine with water and cold winters don't mix. I would check the block over thoroughly. If you do get it to turn over by hand and are going to run it, I would change the impeller out. It's cracked from sitting so long and the motor will overheat quickly if its not working. It's not that hard of a job to do.
 
Good info, He had pulled the waterlines off. Im guessing to winterize it. It was kept in Murrells Inlet for the past 5 years but never put in the water down there. It gets cold down there,but not block cracking cold (I hope). I dont think it had enough water in it to freeze the block. The oil pan doesnt seem distorted either. I must note, it was uncovered and the engine cover was off. He had wrapped the carb, but who knows...

How much ATF should I put in each cyl? Ive seen alot on the webs about Marvel Mystery oil. Does this do the same?

I may wind up changing the intake manifold too. It still has the cast iron intake. and every bit of weight savings matters lol. First wanna make sure it will run.
 
How "covered" was the carb? Could rain water fall into the motor? If so, that's the source of your water, and the motor is probably brimming full. Pulling the valve covers will give you a better idea. If there's been more than condensation in there, the rockers will look like they've been at the bottom of the sound for the last five years.

I'd fill the cylinders with however much oil they'll take. Some will take nearly a whole quart, others won't take hardly any, but fill them to the brim so that you're getting as much of the cylinder wall coated as possible, and you're sure that there's enough to soak between the rings and the cylinder wall.
 
It has a Mercruiser Flame Arrestor Air filter on it and wrapped in plastic. So no water directly down the carb. That I know of. Im definitely pulling the covers to make sure no valves are stuck open.
 
I've used Marvel mystery oil before. It works but is slightly more expensive than ATF. I would also check out the bellows as well to see if they are in good condition. With it sitting for 5 years, they could be pretty brittle and would leak etc. Like @shawn said, pull the covers and look at the top end of the of motor. I got an older boat for free from my wifes grandpa that had sat for 10+ years under a carport. Motor was seized up. We used the marvel mystery oil/ATF and let it sit for a week. We could turn it over by hand after that, so it does work.
 
RobMcBee said:
It has a Mercruiser Flame Arrestor Air filter on it and wrapped in plastic. So no water directly down the carb. That I know of. Im definitely pulling the covers to make sure no valves are stuck open.
Click to expand...
that is just a spark arrestor most i/o dont use any kind of conventional air filter.

ill second changing all the bellows. the kit is like 75 bucks and ill take a couple hours including pulling the outdrive but thats a good time to change the u joints or at least inspect them. on mercrusiers there are three bellows one for the drive shaft, one for a cable? its small, and the third is for exhaust. if the drive shaft bellow has a leak the boat will sink... fast.
 
Loganwayne said:
that is just a spark arrestor most i/o dont use any kind of conventional air filter.

ill second changing all the bellows. the kit is like 75 bucks and ill take a couple hours including pulling the outdrive but thats a good time to change the u joints or at least inspect them. on mercrusiers there are three bellows one for the drive shaft, one for a cable? its small, and the third is for exhaust. if the drive shaft bellow has a leak the boat will sink... fast.
Click to expand...

Yup, learned that the hard way, luckily we had a working bilge pump that got us back to the ramp. I forgot about the U-joints. They can make quite a racket when they start to go. Mercruisers are pretty easy to work on and parts availability is very good. For the impellor, make sure that the shaft it rides on is free of any burrs etc when you replace it.
 
It had to be run to make milk. Just dumping water in oil doesn't make milk. Just my .02€. X4 or whatever on marvel or atf, done it on a tractor that had sit uncovered for a year and stuck, run fine afterwards.
 
Thanks for the info on the bellows. I didnt even know about that. This is why I ask questions. Im gonna make sure I can get it running before I sink any money into the outdrive or interior though. I know its gonna need a new bilge pump also. I dont really know if this one is bad or not but its old and Im not taking chances once i have it on the water.
 
Bilge pumps are essential and are pretty cheap to wire in. I would focus on making sure the motor is in good working order. You can always run it for short cycles on the trailer without water. If you want to check impellor operations, hook the hose clamp up to the water ports on the stern and it should be very noticeable with water flow. Even if the impellor is functioning, I would still replace it since it sat for so long. For the bellows, you can always back the boat into the water, leave it on the trailer and check for leaks.
 
Spend the extra few bucks when it's time with the Bilge and get one with an auto cut on if water gets to it.
We replaced the one on my dads boat and didn't and got a couple of inches of rain one night and sunk the boat enough to get the starter submerged and had to get a new one



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all good info for this first time boat owner. I do plan on getting the engine going first like I said above. If its a cracked block or something Im going to try and replace it. Either way I'll still have less in it than buying one similar to this one.
 
Ordered an oil exchange pump. Figured Id go ahead an spring for a decent one since I can probably use it for other things. Illl update once it comes in and I can suck out this goop. Thanks guys.
 
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