Help Carb Problem ??? (i think)

[jedwards1980]

My buddy has a boat with a ford 302, and what we think is a carter 4bbl carb. number on carb is 9600s 0283 located on left front bottom of carb. Problem we are having is runs fine until we get into four barrels. once in four barrels runs 3 to 4 mins while in 4bbl and then boggs down and backfires. adjusted fuel pump from 7psi to 8psi with no change. Any ideas

 

[NHGuy]

Re: Help Carb Problem ??? (i think)

I'd check fuel supply for restrictions, change all filters and check their contents. Check that the tank vent isn't clogged, check that the anti siphon valve is clean, and check that the tank has no crud in it.
You can eliminate the supply lines and fuel tank by running a small side tank directly to the fuel pump to see how the motor does on the secondaries that way. If it keeps up then you'll want to find out why.
Also, if there is a small amount of leakage in the fuel line it could be sucking air instead of fuel under the heavier fuel demand - where you are getting trouble.
And don't just go by my advice, a lot smarter folks than me will be along with input.

 

[jedwards1980]

Re: Help Carb Problem ??? (i think)

The filters are new and the fuel pump and regulator are also. Lines all appear tight. I will try a secondary tank the next time we go out. any other ideas please feel free to spitball.

 

[dollarten]

Re: Help Carb Problem ??? (i think)

My buddy has a boat with a ford 302, and what we think is a carter 4bbl carb. number on carb is 9600s 0283 located on left front bottom of carb. Problem we are having is runs fine until we get into four barrels. once in four barrels runs 3 to 4 mins while in 4bbl and then boggs down and backfires. adjusted fuel pump from 7psi to 8psi with no change. Any ideas

I am pretty sure you have Holley carb on your boat I would make a tee in the fuel line and see how fuel pressure you really have . Just because you dialed in more pressure does not mean you have the pressure at the carb . You might want to branch in to the fuel line by the fuel pump or even the carb fitting . I am sure that the line is a 5/16 inverted flare fitting Quite common

 

[jedwards1980]

Re: Help Carb Problem ??? (i think)

I'm not sure i quite understand. I have a presure gauge in line between the pump and carb. why wouldn't it be 7psi at the carb still?

 

[Bondo]

Re: Help Carb Problem ??? (i think)

My buddy has a boat with a ford 302, and what we think is a carter 4bbl carb. number on carb is 9600s 0283 located on left front bottom of carb. Problem we are having is runs fine until we get into four barrels. once in four barrels runs 3 to 4 mins while in 4bbl and then boggs down and backfires. adjusted fuel pump from 7psi to 8psi with no change. Any ideas

Ayuh,.... Welcome Aboard,.... Ya want 5 psi... That's the carb Merc puts on their Chevys..

Check for a vacuum leak on the suction side,... might be suckin' air, at hi-demand...

 

[jedwards1980]

Re: Help Carb Problem ??? (i think)

I've never really messed with carbs. which side is suction side and what step to check for leak. Everyone's help is greatly appreciated!!! And are you saying that I'm right in guessing carter carb?

 

[Bondo]

Re: Help Carb Problem ??? (i think)

I've never really messed with carbs. which side is suction side and what step to check for leak. Everyone's help is greatly appreciated!!! And are you saying that I'm right in guessing carter carb?

Ayuh,... It's actually the Merc/ Weber Carter clone,..... exact copy of the Edlebrock performer..

In the Adults Only section is a fuel system testin' thread...

 

[Eric 3.7LX Alpha 1]

Re: Help Carb Problem ??? (i think)

Your having the problems when the 4-barrel kicks in, then I would have the gauge on there when the 4-barrel kicks in.
7-psi at idle might not be there at WOT.

 

[achris]

Re: Help Carb Problem ??? (i think)

My buddy has a boat with a ford 302, and what we think is a carter 4bbl carb. number on carb is 9600s 0283 located on left front bottom of carb. ...

And are you saying that I'm right in guessing carter carb?

Oh boy!!! Now we are guessing which carburetor we have... Can we also have a guess at what engine it is?

Some facts....

Merc finished with Ford blocks in 1977....
Merc FIRST used the Weber/Carter/Edelbrock in 1992 (I might be a year out)...

So, somewhere along the line we have either a misidentified engine, a misidentified carburetor, or a bastard child that some hack has thrown together....

And if it is a Ford block, with a Weber carb (mud in the eye to the aforementioned 'hack'), then your problem could well be a jetting.... :facepalm:

Here's another one worth asking.... What are you using as a fuel pump (electric or mechanical)?

Chris........

 

[achris]

Re: Help Carb Problem ??? (i think)

Ayuh,... It's actually the Merc/ Weber Carter clone,..... exact copy of the Edlebrock performer..

And here I was, all this time, thinking the Edelbrock and Weber were a copy of the Carter AFB.... Well, there you go...

 

[Bondo]

Re: Help Carb Problem ??? (i think)

Originally Posted by Bond-o
Ayuh,... It's actually the Merc/ Weber Carter clone,..... exact copy of the Edlebrock performer..

And here I was, all this time, thinking the Edelbrock and Weber were a copy of the Carter AFB.... Well, there you go...

Ayuh,... You've got it right Chris,... Sorry if my wording is confusin'...

Yes, they're All Carter AFB clones...

 

[dollarten]

Re: Help Carb Problem ??? (i think)

If it is a Carter carb , did they not have a secondary air valve that slowly opens up so you don't get that bog that is being discussed ? Any 4 bbl. carb needs some kind of an assist to make the transition to the secondary's Either an accelerator pump or that back to barrels or an air valve to slow the fuel air mixture slowly open so the engine maintains vacuum. On the Holley carbs they have what is called a vacuum secondary . This a vacuum delay mechanism that slows the secondary opening and sits on the side of the carb

 

[achris]

Re: Help Carb Problem ??? (i think)

If it is a Carter carb , did they not have a secondary air valve that slowly opens up so you don't get that bog that is being discussed ? ...

Yes... They do...

 

[jedwards1980]

Re: Help Carb Problem ??? (i think)

Thanks for all the help. If the weather holds out this weekend we are gonna go out and try some of your ideas. starting with 5 psi and then moving from there. I'll let you all know what it was.