Oil leaking from exhaust

[Aikijitsu66]

Hi,

I have beta marine38 oil is leaking from exhaust its defo oil not soot and water, engine starts fine but sounds muffled, some loss of power, but no excess smoke just a puff on start up oil not contaminated with water and vis versa,and suggestions

[Boater Sam]

3 hours ago, Aikijitsu66 said:

Hi,

I have beta marine38 oil is leaking from exhaust its defo oil not soot and water, engine starts fine but sounds muffled, some loss of power, but no excess smoke just a puff on start up oil not contaminated with water and vis versa,and suggestions

How many hours has it run? How did this start, did you notice a loss of power first?

Apart from a heavily worn engine it could be a blocked crankcase breather or pipe, a blocked air filter, overfilled sump etc. The "sounds muffled" could be a big clue, has anything covered the air intake?

[Tony Brooks]

Wet or dry exhaust? If wet it could be an oil cooler leaking.

[Bee]

If it doesn't smoke when running it is likely that the internals - gaskets, pistons, bores, valves, all the scary stuff is fine, water and soot mixed can make a pretty good imitation of oil but I would check the oil levels in the engine and definitely the gearbox if the gearbox oil is cooled then air filter (as its easy) then think about the O rings on the heat exchanger and oil cooler.

[Aikijitsu66]

Just had a thought  is there any possibility this could be over filled gearbox oil,? Fist noticed lack of power on cut when there were masses of leaves, so I assumed this was cause because if I reversed prop it cured it for while, air filter is clean, this occured after I stopped up gearbox oil, wondering now if I over filled it

[Aikijitsu66]

If this was bike engine, which I'm more familiar with, I'd say the muffled engine sound was because it's not getting a clean burn or plugs blacked or not firing right

[blackrose]

1 hour ago, Aikijitsu66 said:

Just had a thought  is there any possibility this could be over filled gearbox oil,? 

 

Have you checked the gearbox oil level? Not sure how gearbox oil could get into your exhaust though.

33 minutes ago, Aikijitsu66 said:

If this was bike engine, which I'm more familiar with, I'd say the muffled engine sound was because it's not getting a clean burn or plugs blacked or not firing right

 

Have you checked the air filter? Assuming it has one.

[Tony Brooks]

A muffled exhaust sound? Just wondering if something is restricting the exhaust so back pressure past the firing piston may be pushing oil past the pistons on the induction stroke. Possibly a collapsed silencer inside. Its a long shot but about the only think I can think of that may muffle a dry exhaust sound. If it is  a wet exhaust the may be other things related to exhaust back pressure.

 

I can't see how overfilling the gearbox can get oil into the exhaust.