'96 Mercruiser 3.0lx flooding while off

[Denraweb]

Hey guys, been searching around for awhile and I can't really find too much. Just picked up a bayliner with a 3.0l mercruiser in it. Wasn't getting fuel, so I replaced the fuel pump fuel filter (inside the bowl) and now I get fuel. Got it to fire up twice in the span of a few minutes, then nothing. Choking it and leaving it in neutral. Won't start, kick, or anything. Just cranks. If I let it sit for some time, it will start up for a few seconds, and then die. Noticed that after I stop trying, there is fuel pouring into the carb from the venturi (?). It will leak for about 10-20 seconds after trying to crank then drip slowly for a minute until it eventually stops. The carburetor was just rebuilt for this reason with a sierra rebuild kit. I'm gonna check float level and see if I can find out how to check the choke (electronic, push button right on the pivot of the throttle lever by the steering wheel). Anything else that I should be checking? Boat sat for over a year until I got it. Thanks.

 

[achris]

Hello Denraweb, and :welcome: to iboats...

Sounds like the fuel pump diaphragm has ruptured and it's now doing what it supposed to do, flood the engine...

You'll find a yellow tube running from the bottom of the pump to a fitting on the side of the carb. If it's full of fuel, there's the problem...

Chris..........

 

[alldodge]

Think you need to rebuild the carb. The float is not shutting off the fuel

 

[Bondo]

and see if I can find out how to check the choke (electronic, push button right on the pivot of the throttle lever by the steering wheel). Anything else that I should be checking?

Ayuh,..... Welcome Aboard,.... Sounds like ya got a junkyard dog,... whatever parts were layin' 'round,.....

Yer choke shouldn't have a push button, at all,......
'n that makes everything on the boat, Suspect,....

It sounds like the carb rebuild was a failure, so revistin' it to make sure it's Right is step 1,....

You also have to advance the throttle when startin' a carbed motor,......

 

[wahlejim]

Bondo I think he is talking about the button on the throttle to keep it from going into gear.

This is not an electronic choke. push button and advance the throttle all the way to set the choke. If it is electronic, Bondo is right.

 

[Bondo]

Bondo I think he is talking about the button on the throttle to keep it from going into gear.

This is not an electronic choke. push button and advance the throttle all the way to set the choke. If it is electronic, Bondo is right.

Ayuh,..... I see an Outboard control when I read that sentence,..... a switch for a solenoid choke,.....

 

[Denraweb]

Hello Denraweb, and :welcome: to iboats...

Sounds like the fuel pump diaphragm has ruptured and it's now doing what it supposed to do, flood the engine...

You'll find a yellow tube running from the bottom of the pump to a fitting on the side of the carb. If it's full of fuel, there's the problem...

Chris..........

Yup, fuel line that goes back is full of fuel. Thanks! Gonna try to find a replacement. Maybe rebuild if possible?

And yes, the button I assumed was a choke is what you guys said it is. Definitely not a junkyard boat. Main reason I bought it was because no one ever had it and started messing with it doing weird stuff. It's completely stock and factory from 1996, all matching numbers and all original parts (not really a good thing sometimes lol). And sorry, I couldn't figure out how to quote multiple responses to thank everyone individually, but thanks to everyone! Hopefully that's all I'll need now!

 

[achris]

Yup, fuel line that goes back is full of fuel. Thanks! Gonna try to find a replacement. Maybe rebuild if possible?...

Fuel pumps are generally not rebuildable. Main reason, safety. The part number for the one you're going to need is -42725A3. It's available here on iboats, just click on THIS link....

Chris.........

 

[havoc_squad]

If you replace the old mechanical fuel pump gasket that mates against the engine block, make 100% sure you put the right fuel pump gasket part # on since it is the mechanical version, otherwise your fuel pump will over pressurize your carb and it will flood it with too much gas pressure.

 

[savetexomabeaches]

Mine is a 3.0, was doing the same thing. Float stuck. Mine wouldn't start, unless you tapped on the carb. Then when you'd shut it down, fuel would pour out of the carb. Cleaned carb, worked right again.. My fuel pump diaphragm did eventually go out too, and was dumping fuel through the hose into the carb.

EDIT: I've had to edit this so many times because I cannot read. LOL I was able to rebuild my pump (I had spares). I wouldn't advise it, I'd just replace it new.

 

[Denraweb]

Fuel pumps are generally not rebuildable. Main reason, safety. The part number for the one you're going to need is -42725A3. It's available here on iboats, just click on THIS link....

Chris.........

Thanks! I bought one before I saw your reply. I bought the same one on amazon for about $20 more. 2 day shipping helped lol

If you replace the old mechanical fuel pump gasket that mates against the engine block, make 100% sure you put the right fuel pump gasket part # on since it is the mechanical version, otherwise your fuel pump will over pressurize your carb and it will flood it with too much gas pressure.

Gotcha. I'm wondering if I installed the right one now lol. I used the one that matched the best on top of the big spacer gasket.


Thanks to everyone else for the help! I replaced the fuel pump and it fired up like a champ. No more flooding and it'll actually idle now. I just need to adjust/tune the carb to get it perfect.