Hard Starts and Loss of power

[LKing13]

Hey everyone,
I just recently bought a 1996 Bayliner 2250 with the 5.7 Merc in it. (I’m familiar with diesels not gas engines so bear with me) This morning I fired my boat up before heading to the lake, worked fine, got out there and it would crank but would not even try to turnover. I got into it and noticed my carb was flooded out and figured I just gave a little much gas trying to start it, but my choke plate also wasn’t opening all the way, let it breath for about 5 mins and after maybe 5 seconds Of cranking it kicked over and started up. Everything was fine, got to the back of the lake and when we tried to start it again the same thing happened. Got it running and on the way back sitting around 4500 rpms it would cut out and lose power. If I backed off it would gather itself and be fine. Got about 100 yards from the ramp and it just completely died. After looking at the carb again I noticed my fuel pump breather tube was pumping gas into the carb! It’s also idling very high at times (around 2,000-2500) so I’m wondering if my diaphragm on the mechanical fuel pump is shot or if I should be looking into adjusting my carb. Thanks for any input.

 

[Rick Stephens]

I thought a '96 only came with electric fuel pump... but, if your's is mechanical and the clear line from it to the carb is pushing fuel then the diaphragm in the pump is split and you need a new fuel pump. That's the first thing to correct before even thinking about carburetor.

For me, I'd plan on doing a carb rebuild anyway.... but I'm an old guy who grew up on carbed pickups. Not a big deal to get a rebuild kit and disassemble, clean perfectly, make every passageway clear, set float height and reassemble. New to you boat needs ALL the regular maintenance items done. You gotta assume previous owner did none of them.

Best of luck to you. Right place to ask questions.

Rick

 

[LKing13]

Thanks Rick! Seems like every day I’m figuring out something else this yahoo didn’t do! I already have a fuel pump I bought last week when I suspected it was going out, gonna try to tear into it tomorrow and hopefully get some good results.

 

[Baylinerchuck]

I second what Rick stated. Carb rebuilds are pretty easy to do, and you never know what a failing pump pushed into the carb. Plugs, wires, fuel filter etc should also be on the agenda for the motor.

 

[LKing13]

Update: just got the new pump in, starts up great with an occasional backfire before it runs, I’m thinking with a pump providing the correct amount of fuel my air/gas ratio is rich. Also idles really high around 3,000 rpms. Going to tune on the carb tomorrow. See if I can’t get to the bottom of it.