hickup

[Mike Mayer]

my stock 53 ford with a 94 two barrel hickups between shifths. and sometimes on take off . This is at running temp. I need help.

 

[Flathead Fever]

With the engine off, look down in the carb and see if the accelerator pump is squirting when you move the linkage. It provides an extra squirt of fuel to prevent a hesitation as the carburetor switches between the different fuel circuits. When coming off of idle or a closed throttle plate like when your shifting, the engine is momentarily starved for fuel as the fuel flow in the carburetor catches up with the air flow. Without that extra squirt from the accelerator pump it creates a lean condition and a large enough lean condition will cause a backfire to come up through carb and spit out a flame. If the carb sits for a long time the accelerator pump's piston will shrink and no longer make a seal or they get cracks. Once that happens it can't push the fuel out. That's where I would check first. Then I would check the timing.

 

[51 MERC-CT]

Check pump stroke. (no bloviation)

 

[Mike Mayer]

thank you both now I have a place to start

 

[Flathead Fever]

Check pump stroke.


Mike has an excellent suggestion. 99% of what I have worked on were fleet vehicles. So everything was always the way it was when it left the factory so I don't think about stuff l like that. If nobody has ever touched a vehicle you know at onetime it ran fine just the way it is so something has failed. Once other people have had their hands on something you never know what they have done? They could install the accelerator pump linkage in the wrong position. They could put the wrong power valve in it. They could have changed the jets. It was a common practice to go buy a rebuilt carburetor and exchange yours. Who knows what was done to that rebuild. If someone has been there before you, whatever they touched last is a good place to start looking for the problem. If nobody has ever touched the vehicle then a part has worn-out. The problem with flatheads is somebody that didn't have a clue what they were doing has most likely messed with it sometime in its life, plus everything is also worn-out on it.