Carburetor help

[AJ Desalvo 27]

Happy Friday.

I recently acquired an 86-87 310-8.

The engine has an aftermarket carburetor on it. The float bowl continues to leak fuel after multiple attempts to repair with different gaskets.

Any chance you folks could send some pictures of the oem carburetor?

I think it is a 47-853-25S

Thanks in advance. 

[ebinmaine 71,763]

1 hour ago, AJ Desalvo said:

float bowl continues to leak fuel after multiple attempts to repair with different gaskets

 

I make no secret about the fact that I'm not a fan of these aftermarket carburetors. I don't seem to have great luck with them. Others do perfectly fine.

That said, a few different things come to my mind.

 

 

Have you verified with a piece of glass that the float bowl is flat?

 

Quite often a constant leak from the carburetor bowl is not so much an indicator of that gasket being bad but that perhaps there is some schmmuutz causing the needle and seat to not close correctly.

 

Have you verified that the receiving Groove for the float Bowl is also flat by inserting the bowl in there without a gasket to check for spacing differences?

 

 

Have you replaced all the fuel line?

Have you added a good quality fuel filter?

Have you removed and cleaned out and rebuilt the fuel pump?

Have you done the same treatment for the fuel tank?

 

 

 

[AJ Desalvo 27]

Yes, mostly except for rebuilding the fuel pump.

The leak is at the bottom of the bowl at the screw and gasket.

9 minutes ago, ebinmaine said:

 

I make no secret about the fact that I'm not a fan of these aftermarket carburetors. I don't seem to have great luck with them. Others do perfectly fine.

That said, a few different things come to my mind.

 

 

Have you verified with a piece of glass that the float bowl is flat?

 

Quite often a constant leak from the carburetor bowl is not so much an indicator of that gasket being bad but that perhaps there is some schmmuutz causing the needle and seat to not close correctly.

 

Have you verified that the receiving Groove for the float Bowl is also flat by inserting the bowl in there without a gasket to check for spacing differences?

 

 

Have you replaced all the fuel line?

Have you added a good quality fuel filter?

Have you removed and cleaned out and rebuilt the fuel pump?

Have you done the same treatment for the fuel tank?

 

 

 

 

[ebinmaine 71,763]

1 minute ago, AJ Desalvo said:

Yes, mostly except for rebuilding the fuel pump.

The leak is at the bottom of the bowl at the screw and gasket.

 

 

 

On the original carburetors there's just a thin  gasket washer between the head of the bottom bolt and the carb bowl.

Likely nothing on the inside. 

Perhaps the bottom of that pickup tube has been scored or was not cast correctly as new.

[AJ Desalvo 27]

3 minutes ago, ebinmaine said:

 

 

On the original carburetors there's just a thin  gasket washer between the head of the bottom bolt and the carb bowl.

Likely nothing on the inside. 

Perhaps the bottom of that pickup tube has been scored or was not cast correctly as new.

I will take a closer look.

Edited Friday at 04:58 PM by AJ Desalvo

[squonk 43,304]

Fuel bowl retaining nut gasket. I have worked on stuff like this for over 50 years. The new gaskets today just don't seem to seal like the old ones. Nut too loose and it leaks for sure. Too tight distorts the bowl. I've even tried a new bowl and nut. I reuse the old gasket if I can now and coat the sealing surface on the bowl where the nut gasket seals with Permatex Aviation sealant. 

[oliver2-44 10,554]

23 minutes ago, squonk said:

 coat the sealing surface on the bowl where the nut gasket seals with Permatex Aviation sealant. 

But don't get any on the threads of either part