Brown Sludge

TriadSteeler

Petty Officer 1st Class
Joined
Oct 26, 2006
Messages
237
1974 Merc 500

I have researched the brown sludge on this forum and responses seem split between un-combusted fuel/oil/water and gear oil/water.

This motor has been dormant for 10 years. I have rebuilt the carbs, fuel pump, new fuel lines, wiring, and water pump & impeller. Note: I was running a rich mixture 24:1 since the engine sat so long

The sludge issue is really prevalent when running in the barrel. It comes out of the prop and exhaust ports and collects within 2-3 minutes on the surface of the water in the barrel. When running on the muffs there is only a little coming out of the prop. It also smells like gas, but is also oily to the touch.

After running it, I drained the lower unit and there was absolutely no water in the the LU lube. I'm guessing due to the rich mixture and running at idle, that it is uncombusted fuel/oil.

Also, can one of those cheapo vacuum pumps from Harbor Freight be adequate to perform a vac test on the lower unit, or would it be a waste of money provided I made a fitting to screw into the fill hole.
 

Laddies

Banned
Joined
Sep 10, 2004
Messages
12,218
Re: Brown Sludge

Thats where the sludge came from, I don't know which gauge your talking about as I don't have a catalog but without some adapting probably not.
 

TriadSteeler

Petty Officer 1st Class
Joined
Oct 26, 2006
Messages
237
Re: Brown Sludge

Thanks Laddies.

It is a vacuum pump to bleed freon compressors in cars, fridges, AC units. There is also a gauge you can buy that can be teed inline. If it would work, $11 would be worthwhile investment. I know some type of quick connect fitting would need to be soldered to something like an old drain plug with a hole drilled in the center.

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=96677
 
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