Outboard Cleaning

I have been posting a lot lately as I now have three 9.9/15 hp OMC's I am in the process of fixing up. In doing so I have spent a lot of time running them in a barrel, and as you know, doing so at lower rpms for even short periods of time creates some very oily water. Of course when you remove them they are a slimy mess. I typically just hose them off with some good water pressure and let them "self clean" when I run them on the boat but that is not a very good solution. What would be the best and simplest thing to do? Would a coating of engine degreaser and then a rinse do the trick? Is there some special home made solution that works? Or maybe should I just get the car wash bucket and some dawn dish detergent out and give it a hand wash each time I remove it from the tub?

FWIW Simple Green is phenomenonally rated/tested as one of the top degreasers (less excluding any active/volite solvent) and should remove the oil 'slime' easily, but note it surprisingly doesn't rate high as a cleaner.

Be very careful with degreasers and old outboards. Some will take the paint right off your motor. I had an unfortunate experience with a 1955 Evinrude 7.5hp.

Believe it or not WD40 works on the heavy stuff and yes dish soap and water do a pretty good job. WD40 will clean and protect the old paint on the older motors.

Steve A W said:

I put a healthy shot of Dawn dish soap in my test barrel and the motors come out clean.

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I will have to try that - thanks!

Steve A W said:

I put a healthy shot of Dawn dish soap in my test barrel
and the motors come out clean.

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I have used Dawn on a rag on the motor. Your idea sounds even easier tho. Is there any potential of harm to the thermostat or innards of older outboards?

I use foaming gunk engine degreaser comes out good as new

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We use a 100 gal water trough at work, mainly because 100 gal is the smallest we could find that was short enough for me to throw a 25hp motor over it without using a lift.

Running a 25hp 2 stroke for about 10 minutes-at idle even-creates quite a bit of muck on the top of the water. I always use dawn in the tank, problem is, if I'm load testing in gear with a test prop, the dawn makes it bubble up bad, really bad. But it does work to clean the muck off.

What opened my eyes was the time I had a customer walk back to the shop while I was test running a 25 hp 4 stroke. We got to talking while the engine was idling in the test tank, and about an hour later he left. I turned the engine off and waited for the water to settle, but it wasn't real dirty-not much at all on the top of the water. I was amazed! A 2 stroke 25, it'd be a nice sheen across teh top plus the nasty mucky mess that comes with it, what I call tarballs. Black gunky stuff that sticks together and when you pull the motor through it, it sticks to the motor and makes it a nasty mess to clean. But dawn works pretty good, on a rag or sponge, just wipe it down.

Thanks guys! I will definitely try adding dawn straight to the barrel. I'll have to look into Simple Green too. I'll be careful if I do use any degreasers though...I'll need something heavy duty to clean the gunked grease around the pivot tube.