need help!! '91 pro v 150

Here we go,
I have a 91 yam prov 150, I have done everything i know to do, and really need help! First off last weekend while *****ing the engine runs rough all day, when we are starting home engine bogs down and will not gain rpms. When I looked back at the engine the was a cloud of smoke, so i shut it down to see what was going on. took the cowling off and found a lage amount of oil in the bottom of the housing, and oil leaking for the low end of the air silencer. When i finally got the engine back running in lagged very bad for about an hour of running, then all of a sudden took off. Got back to the dock and noticed a extreme amout of black sut around the exaust ports and out of the prop hub. I hope this makes sense to yall!! Please help!!

[boats.net]

The oil tank on engine may be overfilling and fouling spark plugs, check oil system.

Changed plugs and cleaned carbs from head to toe. the gas in the bowl looked really discolored (stained brown) seems to be running better, but still smoking more than other engine. what should i check on the oiling system? took the sending unit out and made sure the float was free. all ok. checked sending unit in full open and full closed position, and found to be the same as the other engine which is running great. (about 3meg ohms) any ideas?

[jb123]

IF you have 2 motors you can swap parts to see which are bad.

did you check oil level when running ?

no issues with the oil pump linkage?