2 barrel carburator problems

[pensacola]

Now I am having problems with the carb. Its a 1999 Mercruiser 5.0 305. It runs for 15-45 seconds than dies. I restart it with the same thing. I tried adjusting the fuel/air ratio and it ran real slow for a while. Then it died again. I could mess with the screw at the front and it would help a little sometimes but not much. It still continued to die. Just before it dies it will raise the rpm's then die. A couple times I would be able to save it by throwing it into neutral. When I would put it in neutral it would go to the idle speed rpm's. Then I put it in gear and it runs for a second real sluggish, revs up and dies. Needless to say I finally gave up and had to be towed in.

 

[rodbolt]

Re: 2 barrel carburator problems

it sounds like either water in the fuel or the electric pump is cutting off, if yours has an electric fuel pump carefully check the oil pressure switch on the side of the block just above the oil filter pad.if yours has a remote mount oil filter just follow the oil lines back to the block.

 

[Don S]

Re: 2 barrel carburator problems

You have a faulty oil pressure switch that controls the fuel pump (electric on your engine).

Temporarially hook the 2 wires from the oil pressure switch together and see how it runs.

 

[pensacola]

Re: 2 barrel carburator problems

Wow that figures. My marine mechanic thought it was the fuel pump cause when we took the line off the carb and tried to start it nothing came out. So I just bought a new $250 fuel pump and that didn't solve the problem. Now he is thinking its a carb problem but I just had the carb rebuilt so I don't think its that. Hopefully its what you say. I sure do appreciate the advice and I will try that tomorrow.

 

[Reel Poor]

Re: 2 barrel carburator problems

when we took the line off the carb and tried to start it nothing came out.

Make sure the purple yellow wire is also connected to the starter properly. While cranking the fuel pump should get it's power from the "D" terminal (in the pic) on the starter. The pump should run while cranking.

 

[pensacola]

Re: 2 barrel carburator problems

Yes it should be. We just replaced the starter also the same day.
I will definetely check it again to make sure. Thats why we thought it was the fuel pump cause it wasn't running when we tried to start it. That would be crazy if thats all it was but I don't think I would be that lucky at this point.

 

[pensacola]

Re: 2 barrel carburator problems

It worked!!! All this time I have been having problems and that was it. Much thanks for the advice. I wish you were in Pensacola,FL you would be my boat mechanic for sure. All this time I have re-built the carb, replaced the $250 fuel pump, pulled the motor and replaced the flywheel and numerous other things trying to figure out the problem. The whole time it was a $30 oil pressure switch causing the problems and a after market starter from Arco. I now have a boat again and can go 55 mph with no problems. I love it. Not to mention we had to get towed in last weekend going camping and the boat wouldn't run. If I would of had a little jumper wire I could of made it in. Thats why experience is the best teacher of all.

 

[Coors]

Re: 2 barrel carburator problems

The techs in here are the best in the industry, and free.
Now shop Iboats for any parts you need.

 

[pensacola]

Re: 2 barrel carburator problems

Thanks for the info. I didn't even know you could buy parts on here. I was too wrapped up in trying to find out what was wrong with my boat to even look at the rest of the site. But thankfully now I have plenty of time to look around.