Carb help.

[bullittwrench]

4412 gas, 30cc accelerator pump. What color cam and in position 1 or 2?

[Lizardracing]

I'd start with the white one on No #1 and see what happens.
If it stumbles try #2 and if that still doesn't work the orange one will on #1.

You only need to feed it what it needs and no more. A tiny bit more is better than less however.

[let-r-eat]

You should use position #1 on the 4412. Brown cam to start on a v8.

[bullittwrench]

With it on the bench. .015 play in the pump arm and brown cam at wot it hangs open. I understand there are no return springs but is this ok?

[let-r-eat]

Most people are measuring the .015 in the wrong place. The .015 is with the throttle wide open. You need .015 left of pump arm travel after you reach full throttle, not before you start actuating the throttle. You should not have any binds.


https://www.youtube.com/watch?v=k-Nx5HEzvlY

[bullittwrench]

Should I be using the linkage that was on the carb for the 50cc pump or the one that came with the 30cc kit? They are quite different. Thanks

[stock car driver]

Why are you removing the 50cc?

[bullittwrench]

Was told overkill for a 2 barrel? I’m just learning. Carbs interest me and I like doing things myself. My friends who have store bought 4412’s have 30cc pumps. If that means anything. Am I screwing up?

[Lizardracing]

All carbs I've ever worked on were 30cc. I can't say I see a reason for the 50cc honestly. Maybe years ago on alky or something I don't know.

[stockcar5]

All my carbs from JDR have 30cc pumps except for my ethanol 4bbl which has 50cc pumps.

[stock car driver]

I would just leave it alone since it sounds like your having issues changing it.

[bullittwrench]

Found my issue thanks to the Holley website. The brown cam I was trying to use is 50cc only. Ordered a 30cc cam kit and down loaded the cam curves chart. Now to do some studying and flow benching.

[let-r-eat]

I misread your first post. I thought you were using 50cc pump. My bad.

[bullittwrench]

No worries. All is well. Thanks