What is causing this sludge?

[ckraker]

1974 135 Evinrude

had the lower unit rebuild last year, I checked the gear oil and it's still clean. Any Idea what might be causing all this sludge? I'm mixing 50:1 and it's running fine. Thanks

 

[Daviet]

Re: What is causing this sludge?

Are you running it on a hose? It looks like unburnt fuel mixed with carbon from the exhaust housing, not uncommon when running on the hose.

 

[ckraker]

Re: What is causing this sludge?

No I'm not running it on the hose. Trolling in a lake. I have always had some dripping but this seem excessive to me. Maybe not?? What might cause an excess of unburnt fuel?

 

[Daviet]

Re: What is causing this sludge?

Is the engine running up to temp, a cold running engine will do that at times.

 

[ckraker]

Re: What is causing this sludge?

I guess I can't say for sure if it's up to temp. I don't have a gauge. The flywheel is really hot after it runs if that is any indication.

 

[ckraker]

Re: What is causing this sludge?

Does anyone think I should be concerned with this-- or should I just buy some oil dry and be happy?

 

[MovingTarget]

Re: What is causing this sludge?

I would be concerned, but I don't know what would cause it either, sorry.

It almost looks like the lower unit fluid is leaking out.... not sure.

 

[boobie]

Re: What is causing this sludge?

I'd get a cheap I R temp gun and check the running temperature. If you have a cold running mtr this is no good for it.

 

[Daviet]

Re: What is causing this sludge?

It looks like it's leaking out of the exhaust housing drains. If the lower unit does not get any water in it, put a drain pan under it and forget about it.

 

[boatlemmy]

Re: What is causing this sludge?

i guess if you checked the gear oil and its clean that isnt it but it sure looks like gear oil with water mixing in. i had an older motor that would get some water in and the gear oil looked exactly like that. usually unburned fuel with exhaust will look dark grey or black.

 

[ckraker]

Re: What is causing this sludge?

How would gear oil get up there anyway? Aren't those drain holes above where the gear oil is?

 

[ckraker]

Re: What is causing this sludge?

Just took it out again this morning-- It runs almost perfect and the temperature seems good. Any other suggestions?

 

[hidef]

Re: What is causing this sludge?

As Boobie said get an Infrared Thermometer and check the temp of the head and block. It should read somewhere around 145 degrees if not it is running cold. That is unburnt gasoline and oil dripping out of those holes. What are you using for two stroke oil?

 

[194269]

Re: What is causing this sludge?

Looks like gear oil to me, the gear case seal below the water pump is bad. The water pump is forcing water into the gear case and the gear oil is coming back up and out seal. When running you are pressurizing the gear case, and when you stop gear oil (being lighter then water) is forced back out and then drains out the holes.