please help 86 15hp evinrude milky stuff inside prop exhuast

[little lulu 2 boat]

milky oily stuff building up inside lip of prop is this ok if what could it be how do i fix it

 

[rolmops]

Re: please help 86 15hp evinrude milky stuff inside prop exhuast

That is not a problem.
When you run at a low rpm there is not a whole lot of pressure behind the exhaust gas in the exhaust housing which is filled with water while the engine is in the water.The unburned fuel floats on this water and when you accelerate or when you pull the boat out of the water this oily residue (milky clumps) will get out of the exhaust housing and often stick to the lower unit.
A good way to get rid of it is by running at a high rpm for a while and this will blow the gunk right out of the exhaust housing.

 

[backyard mechanic]

Re: please help 86 15hp evinrude milky stuff inside prop exhuast

Most likely not a problem but heres how to determine if it is;

1. Check compression paying attention to low readings or nearly the same low readings.
2. Check for water in the drive/lower unit oil.

Milky looking oil is oil mixed with water. That can mean unburned 2 cycle oil or gear oil with water in it.

The compression test tells you if there is a problem with a blown head gasket allowing water in the cylinders or oil into the water passages. The unburned fuel could be from a bad lower crankcase seal or simply fuel and oil unburned and running down the exhaust tube.

A bad seal could be cause for water in the lower unit. Worst case; a hole in the case somewhere. A pressure tester will help with that.

Lots of possibilities, likely nothing to worry about if the lower unit and compression tests are OK. Did the engine run OK?

 

[backyard mechanic]

Re: please help 86 15hp evinrude milky stuff inside prop exhuast

Most likely not a problem but heres how to determine if it is;

1. Check compression paying attention to low readings or nearly the same low readings.
2. Check for water in the drive/lower unit oil.

Milky looking oil is oil mixed with water. That can mean unburned 2 cycle oil or gear oil with water in it.

The compression test tells you if there is a problem with a blown head gasket allowing water in the cylinders or oil into the water passages. The unburned fuel could be from a bad lower crankcase seal or simply fuel and oil unburned and running down the exhaust tube.

A bad seal could be cause for water in the lower unit. Worst case; a hole in the case somewhere. A pressure tester will help with that.

Lots of possibilities, likely nothing to worry about if the lower unit and compression tests are OK. Did the engine run OK?

 

[little lulu 2 boat]

Re: please help 86 15hp evinrude milky stuff inside prop exhuast

thank you you guys are very helpful yes motor run great seems to get a little hot at high rpm but does not stop running i just decarbed it about to go out and run it hard and see what happens

 

[little lulu 2 boat]

Re: please help 86 15hp evinrude milky stuff inside prop exhuast

ok i decarbed motor runs better than ever run wot about 3miles didnt run hot are anything and miky stuff gone thanks