1920 Holley Carb on the M715

[Knottofs]

Put a new needle valve in, and it keeps sticking shut, running 4-½ psi fuel pressures. Its not the float closing it, its just sticking shut. Any ideas on freeing it up? Thanks, Nate

 

[Barrman]

Can you actually hear the float flopping around if you hold the carb in your hand and flip it over?

If not, check for the float hitting the bowl. I fit is, then try this.
Blow through the fuel inlet with the carb upright and listen to the air flow. Keep blowing as you turn it upside down. The air flow should stop. Keep blowing and turn it right side up. It should start again.

If it doesn't and the float is flopping. Use some B-12 to un gunk the needle. If that still doesn't help. Make sure you have the little wire that connects the top of the needle to the float. That allows the weight of the float to open the needle valve. If you don't have this, buy one or make one from soemthing small like the spring in a ball point pen.

 

[Knottofs]

If I take the float cover off, and blow into the fuel inlet, the needle sticks when the float is down. The needle will eventually pop open, but it takes a lot of lungpower PSI. Then when I lift the float, it closes again, but then it sticks again when the float goes down, when I blow in it. It has the spring under the float, and the float level is set at 3/16”. But I don’t see any wire connect the float to the needle valve. Ive rebuilt the carb a couple of times before, and have never had this problem. Ill try that B-12 to un gunk the needle.
Thanks, Nate