Grey Sludge from exhaust (propeller)

I’ve had a bit of a busy year. Overseas holiday, been in hospital etc etc.

Haven’t used the boat since beginning of the year and then only had a couple of short runs.

Enough of the bleeding heart stuff.

Couple of days ago I thought I better kick the boat over and get it ready for some serious fishing/boating over the summer.

Took me quite a while to start the Johnson 115 hp Oceanpro (2 stroke), in the front yard with muffs on and when I did there was a lot and I mean a lot of smoke.

I let it idle for about ten minutes plus. Eventually the smoke settled down to what I’d call normal.

Appeared to run well and had a very good water flow.

After I turned her off I noticed on the ground in front of the propeller/exhaust was a grey coloured sludge (should have taken pictures).

I know it’s hard without pictures but anyone have any ideas on what this sludge may be.

Thanks






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just oily 2 stroke slime left over in the exhaust tube and leg. i get it from time to time, usually a good blast on the water clears it out!

Gray sludge is water mixing with oil, There are two locations for oil, gearbox and powerhead, i have had twice a corroded exhaust wall on the powerhead and it allowed the oil to mix in the combustion chamber and it spewed down the exhaust and out the propeller

depends how much your talking about tho mine was heaps i removed my spark plugs as a quick diagnosis than cranked the engine over and the gray milky stuff came out the spark plug holes

both engines still ran like this too, one was a 15hp Evinrude the other was a 30hp Suzuki both 2 strokes

Don't worry about it.

It just means the motor is getting lots of lubrication and so will never wear out.

Your more likely to kill your motor by getting a plastic bag caught on the water intake.

My two 115s do it too and my master marine tech says its a good thing!!! and no need to buy new motors............

The old VRO engines did have a check valve in their oil supply system that could leak. Basically resulted in a carbie getting oil in it over periods of sitting thus causing excessive smoking at start up until the oil got burnt off. In a well advanced case (like mine was) it was bad enough to basically mean that that cylinder would not fire. My motor used to run like a hairy 3 legged dog for a couple of minutes but once the oil was burnt off it would then run like a new one for the rest of the day. Eventually I disconnected the oil injection and went back to premix which not only did away with the starting issues all together but also allowed the engine to be idled out of fuel at the end of the day which made starting better again. The oil injected engines so I was informed should not be idled out of fuel as it also leads to excess oil in the carbies and similar start ups. The grey sludge is as mentioned, pretty much normal.

I think it is important to determine the colour of the sludge.....creamy grey or dark grey.
I fit is creamy grey, take the drain plug from the bottom of the gearbox out and check the oil has no water in it.

If you do suspect gearbox oil, get a bit of it on your finger and have a sniff, you'll know straight away if it's gear oil!

Quote:

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Originally Posted by ericcs

If you do suspect gearbox oil, get a bit of it on your finger and have a sniff, you'll know straight away if it's gear oil!

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I’m going to inspect today, for future reference how will I know it’s gear oil from smell.


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Gear oil is the most horrific smelling fluid in any mechanical object

if you crack the drain screw and wind it out just enough to get some oil leaking past, then smell it and you will understand. It should be clear like engine oil, but also will be normal if it is a bit blackish. If it's grey and milky, it means water is getting in, but not necessarily leaking out, t's usually one ore the other, so i doubt it will leak milky oil!

Quote:

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Originally Posted by stevej

Gear oil is the most horrific smelling fluid in any mechanical object

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yes indeed and will need 8 bars of solvo soap to cleanse that stench from your hands. just changed my diff oils yuk yuk spewww

i added a 5 speed to the old cortina and was filling it with fresh oil lying on my back and pumping with one hand and holding the hose with the other

for some reason the hose held the oil back till i moved it and managed to get half a litre of the shit down my arm armpit and chest