454 mercruiser carb issue, please help!!

[12guns]

it's early 90's model and has had it's share of work in the past. The boat was running, but not as it used to. The fuel pump was removed and tested and was shot. The new fuel pump works great, but when wired up, gas started pouring out the top of the carb and a exposed needle inlet. So, stuck float? bad needle? I'm working on rebuild, but may have trouble finding a kit locally.

Can someone breakdown the flow of gas into the carb? Could the new fuel pump be too strong and blow by the needle? I got the top of the carb off and the float/needle out. What do I look for? Sorry I don't have more info on the engine #'s, I'm hoping this in generic enought that someone can break it down for me and walk me through what to look for.
Please help, and thanks

 

[HT32BSX115]

Re: 454 mercruiser carb issue, please help!!

Howdy,

Don't waste your time on trying to fix that carb.

Just send it to http://www.flyingfishcarburetors.com/ and let them rebuild it.


Regards,


Rick

 

[12guns]

Re: 454 mercruiser carb issue, please help!!

My plan was to replace the fuel pump and head to the lake tomorrow...unless I can find a rebuild kit locally I'll be taking the boat to a local trusted boat mechanic to do the rebuild. I can handle it myself, but it's not my boat and if I can't fix it up tomorrow, I'll let the owner deal with it. I would like to find a new gasket and possibly a full rebuild kit. After reading online, I'm pretty sure it's a float/needle problem. I might even take a chance and use the old needle, but I for sure need a new gasket cause the old one tore. Please give me some tips for a quick fix. Where can I find the engine data or the carb data for ordering the right parts?
********
also, Is it possible my fuel pump is too strong? Should it pump all the time or shut off under pressure?

 

[Bondo]

Re: 454 mercruiser carb issue, please help!!

Please give me some tips for a quick fix.

Ayuh,... There probably Ain't a Quick Fix,.... What Carb is it anyways,..??

also, Is it possible my fuel pump is too strong?

Only if it's an EFI fuel pump....
If it's a Carb fuel pump,... No...

 

[12guns]

Re: 454 mercruiser carb issue, please help!!

Ayuh,... There probably Ain't a Quick Fix,.... What Carb is it anyways,..??



Only if it's an EFI fuel pump....
If it's a Carb fuel pump,... No...

Are you saying if the fuel pump is made for Carb vs. EFI? I don't know about the new fuel pump, but based on what I could look up online, the carb requires 5-7 psi and the pump my hardware store ordered looks to be 45 psi. I'm assuming it's wayyyy to powerful and blowing past the needle. Sound possible?
I'm working on getting the right fuel pump. Now that the carb is off, I'm having a kit put in. Should be good to go after that. Any other things to look for?

 

[12guns]

Re: 454 mercruiser carb issue, please help!!

Well, I think it's fixed. Got a new gasket and re installed the Carb. Found a generic fuel pump that is appx 7 psi, runs and idles great. I haven't been able to run it under load, but will be putting it in the water this weekend! Looks like the fuel pump was the problem to begin with

 

[MikDee]

Re: 454 mercruiser carb issue, please help!!

It would help to know what brand carb. it is as Bond-o mentioned
But it sounds like you may have fixed it anyway, good luck, Mike

 

[12guns]

Re: 454 mercruiser carb issue, please help!!

Well, boat ran great for 2 hours. My buddies dad was working on the jet ski while his family from out of town played in the boat. After a couple hours they brought it back-on it's death bed-. They left it w/ a trusted mechanic near the lake. He's good, but may take a while. Looks like the Carb issue is fixed, now on to the next problem.
If I had to guess, it's something internal. The boat owner's son took it out for a spin after de-winterizing the boat. Problem is he forgot to put the main cooling hose back onto the block, so after nearly sinking the boat and it not running over 45 mph, he took it back to the ramp and brought it home. I fear for the worst. I would imagine the engine was pretty hot. We'll see.