Carb Question

[bobs66440]

I am having a bit of fuel seeping from one of the cover screws. Looking at the gasket design, it looks like there is really no way for the gasket to seal the screw with the oval style hole going into the float area. I looked and all the gaskets in the rebuild kits seem to be this way. Is this common or can I use a sealer for the screw?


Also, is there a better barb fitting setup for the fuel inlet? I have to really crank down on the hose clamp (1/4" hose) and it still seeps a little.

[Dietmar]

Several things to look for-
-does your float still have a weight attached on the bottom?

-Have you measured the fuel level AFTER idle? Disconnect the coil wire, undo the four carb screws and hold the top in place, crank the engine over for about 30 seconds ( or less), remove the carb top quickly so no fuel continues to flow into the bowl. With the gasket removed, measure from the body of the carb to the fuel with the end of a caliper. Should be about 9/16 ( .5625) Could be .600 but not less than .5625

-Have you checked the flatness of the carb top?

-Does the needle valve in the top of the carb stick open? Turn the carb top upside down, press on the needle valve, let it go and gently blow into the fuel line fitting. Should restrict blowing.


Sounds to me like the fuel level is too high or the top is warped.

As for the fuel line leak- if it is coming from the hose and not the fitting itself, I would suggest a VW rubber braided hose. With this stock hose, there is no need for a hose clamp once installed ( even though we still run one anyway).

Hope this helps.

Dietmar
www.quixoteracing.com

[Hardingfv32]

And do not over tighten the carb top during re-installation. The screws heads should never look warn or damaged. The lock washers are useless. The screws do not get loose during engine operation. If paranoid... use blue Loctite.

Brian

[bobs66440]

Several things to look for-
-does your float still have a weight attached on the bottom?

-Have you measured the fuel level AFTER idle? Disconnect the coil wire, undo the four carb screws and hold the top in place, crank the engine over for about 30 seconds ( or less), remove the carb top quickly so no fuel continues to flow into the bowl. With the gasket removed, measure from the body of the carb to the fuel with the end of a caliper. Should be about 9/16 ( .5625) Could be .600 but not less than .5625

-Have you checked the flatness of the carb top?

-Does the needle valve in the top of the carb stick open? Turn the carb top upside down, press on the needle valve, let it go and gently blow into the fuel line fitting. Should restrict blowing.


Sounds to me like the fuel level is too high or the top is warped.

As for the fuel line leak- if it is coming from the hose and not the fitting itself, I would suggest a VW rubber braided hose. With this stock hose, there is no need for a hose clamp once installed ( even though we still run one anyway).

Hope this helps.

Dietmar
www.quixoteracing.com

If I turn it upside down and blow through it, the air is very restricted but not completely. A very small amount of air seeps through until I gently press on the needle then it stops completely. If I flip it over then it flows good. I put it back together and checked the float level and it's at about 9/16" (.560"). Do the holes in the gasket need to be elongated like that? The fuel has to be able to leak into the threads of the screw I would imagine...

[Dietmar]

The gasket is the same as we all use, so I do not think that is the problem. The fuel has to get to the top of the carb, so we get back to the carb top possibly being warped.

You did not say if the weight is still attached to the float. Should be epoxy on the bottom of the float.

As Brian mentioned- do not over tighten the screws and after checking the carb top, a new gasket might be in order.

If none of that solves the problem , I would be happy to look at the carb for you.

Dietmar
www.quixoteracing.com

[bobs66440]

The gasket is the same as we all use, so I do not think that is the problem. The fuel has to get to the top of the carb, so we get back to the carb top possibly being warped.

You did not say if the weight is still attached to the float. Should be epoxy on the bottom of the float.

As Brian mentioned- do not over tighten the screws and after checking the carb top, a new gasket might be in order.

If none of that solves the problem , I would be happy to look at the carb for you.

Dietmar
www.quixoteracing.com

Sorry, yes the weight is there. I will check the cover for warpage. Can I just get a gasket or do I have to buy a rebuild kit? Thanks for your help.

[Dietmar]

Pull the two pins and surface with wet/dry paper. 180 is what I generally use.
Gaskets are $2 ea so no need to buy the entire kit.

If you have a gram scale available, what is the weight of the float?

Dietmar
www.quixoteracing.com

[bobs66440]

Pull the two pins and surface with wet/dry paper. 180 is what I generally use.
Gaskets are $2 ea so no need to buy the entire kit.

If you have a gram scale available, what is the weight of the float?

Dietmar
www.quixoteracing.com

Ok, yes I was wondering about the pins. I wasn't aware they will pull out. Perfect. Actually I was looking for the gram scale we used to use for the cub scouts pinewood derby cars but couldn't find it. I'll keep looking. Thanks!