1994 Mercruiser 3.0LX choked

[dlogvine]

I took my 1994 Maxum boat with 3.0L 4cyl Mercruiser to the lake first time. At first the engine ran really well, was doing about 35 mph on WOT, cant tell RPMs since this boat did not come with the tachometer. Then after about 45 mins I stopped the engine and jumped in the water to cool down. When I started it again the engine was starting just fine, but it was choking on about 1/2 of the open throttle. It ran at about 10-15 mph. I looked at the carburetor, opened the adjusting bolt a little. checked all of the ignition connectors. After about 5-6 mins of starting the engine and getting it to the higher gear and engine dying, suddenly on one of the turn ons it started working without a problem and worked well for the rest of the trip, about an hour or so. I noticed there is a little oil leak in the valve cover, but it did not seem to affect the oil pressure and overall the leak in about 2 hours resulted in maybe a fluid ounce or two of the lost oil. I'll change the valve cover gasket tomorrow, but im still concerned about the weird engine choking. Any ideas as to what could have caused this behavior? There was some vegetation floating at the place where I took a swim, so I wonder if anything could have clogged the water intake? And would this have caused this malfunction?
Thank you

 

[wellcraft-classic210]

The performance issue you described sounds like fuel delivery

Their are a lot of possible causes -- here are a few likely ones.

Was you choke on or off ? If it was stuck on or set incorrectly -- that's 1 possibility

Any water or debris in the bottom of the tank gets stirred up on harder runs -- Their could have been water in the fuel filter or barbed fitting " check valve " where the fuel exits your fuel tank. -- that's 2 more possibilities

If it happens again see whats going on with the choke once the engine is warmed up it should be off.

If the choke is OK

Then try swapping the fuel filter or separating the check valve barbed fitting and inspecting the spring loaded ball inside it for debris. The check valve is located where the rubber line connects to the tank




Also

A small oil leak will not cause performance issues.

Do you have a working temp gauge -- If not highly advise you get one.

Not exactly what screw was turned but if its the mixture screw -- that will only affects the idle mixture I

 

[alldodge]

Pull the fuel filter bowl off and pour the contents into something to see if there anything besides clean gas. When bowl is removed it should be full, if not there is cause to look further