Oil running down Exhaust Housing Midsection (unburned 2 cyc. oil or lower unit oil?)

[tlocus73]

Hello,
I've read a few posts I believe were related to what I'm seeing on my engine.

I'm getting a slight oil slick (not much) after running it for a few hours, on the port side of the exhaust housing midsection there is about a 2" oil slick running down.
Not sure if it's coming from the exhaust housing-powerhead adapter, the seal at the top of the exhaust housing midsection or an upper seal from the lower unit gear oil.
Here is a diagram:


Some things I've done and/or noticed that were not necessarily related:
-Replaced thermostats, pressure relief valves, gaskets, valve body, rubber & cork seals and also cleaned out all the deposits inside the thermostat cover.
-Had a small water leak at the bottom of the exhaust cover (large plate between the V4 cylinder banks). I removed both outer and inner plates, removed old gaskets and cleaned out all mineral deposits. Reinstalled adding gasket sealant on both sides of the 2 gaskets and torqued bolts to the specified value...no more leaks.
-While I had the rear lower cover off, I tightened the bolts from the exhaust housing midsection to the exhaust adapter. Didn't check/ tighten the bolts under the front lower cover yet.
-I noticed the oil slick is only running down the port side of the exhaust housing midsection.

Wondering your thoughts on if this is just unburned 2 cycle oil from within the exhaust housing or lower unit gear oil seeping out of an upper seal?

Another diagram:


And another:


thomas

 

[Blazinmonkey]

Re: Oil running down Exhaust Housing Midsection (unburned 2 cyc. oil or lower unit oi

unburnt 2cycle oil...
did you idle much be fore you shut the motor down?

 

[tlocus73]

Re: Oil running down Exhaust Housing Midsection (unburned 2 cyc. oil or lower unit oi

There are a few no wake zones, including one leading up to my dock. Not necessarily idle but I'd say 1400-1600 rpm in forward gear.

Btw, where would this be coming from or what gasket? Would it be the gasket #18 in the exhaust housing adapter (2nd diagram)?
Or possibly that seal right above the exhaust housing midsection in the 1st diagram?

thanks again

t

 

[dragula]

Any results to share? This post is seven years old but I just found a small oil leak from port side of upper midsection. Seems like what your problem was.

 

[GA_Boater]

Any results to share? This post is seven years old but I just found a small oil leak from port side of upper midsection. Seems like what your problem was.

You saw it is 7 years old, so why ask an OP when he left 2 years later?

Closed.