1989 15 hp with oil water mixture leaking around muffler cover

[jwoody]

After running at trolling speed I have a leak around the muffler cover. It looks like a water oil mixture kind of a cream color faom. Anyone know where this is coming from and if it is the kind of fix a novice may be able to do?

 

[kbait]

Muffler cover?
Go to boats dot net (where 'dot' is a period), and look up your model's schematic and give us the actual name of the leaking part, and we'll help!

 

[jwoody]

The leak is coming from around the muffler (part #4 on the midsection diagram from boats.net diagram) on the back of the motor just below the cover latch. There is also a small amount coming out of the exhaust port in the top of the lower unit. From other posts regarding this white foam water oil mixture it may be from unburned fuel which I don?t really understand the mechanics of how unburned fuel can happen. I guess it has something to do with the two stoke engineering. If this is the case are there adjustments to the rich/lean mixture to correct the problem?

 

[175se]

If your running it in a bucket or barrel, youll see that, make sure you have your idle set right. By the way guys the part #4 he is referring to is listed as MUFFLER,exhaust.

 

[jwoody]

I?m not running the motor in a barrel this happened after a days fishing, and I don?t understand what ?youll see that? means.

 

[jwoody]

When you say to make sure I have the idle speed set right would this cause the problem? I use the motor primarily for trolling, sometimes as slow as .8 MPH to 1.8MPH. Would this slow speed cause the unburned fuel to leak out of the exhaust (and I?m still not sure this is the cause)? If this is the cause, is it doing damage to the motor and is there a reason for concern? This has always been a great motor I have never had a problem with it until just a few weeks ago when it wasn?t idling right. The cam roller was bad and once I got that fixed is when this new white foam problem started.

 

[steelespike]

"You'll see that" Means you will see a concentration of unburned fuel on the surface of the water and on the leg in a barrel.
I think it is an exageration of a normal occurrence. It is a concentration of unburned fuel that also occurs in normal operation but is burnt off or washed out
in high speed operation.If the thermostat is bad or missing then operation will be cooler allowing more concentrated fuel deposit.
When oil and water mix you get a milky result. It very likely smells gassy.You might try adjusting the idle mixture but always leave it slightly to the rich side.
If the water is still cold it may exaggerate things.Perhaps whoever worked on the roller changed the idle fuel mixture screw after adjusting things.
Mixture setting and idle speed should be set in gear on the water and un restricted forward movement.
The oily sludge may actually keep some of the fasteners from seizing over the years.

 

[jwoody]

Thanks for the explanation. This makes a lot of sense. I'm going out on Wednesday and will adjust the fuel mixture and see if it makes a difference.