High speed air bleeds

[Aron Gleason]

Secondary side is the likely problem.

Thats what ive been working on too

 

[dvw]

Put the idle bleeds back where you started and see what happens.
Doug

 

[BSB67]

Based on his description, it does not sound like a tip-in issue.

 

[Aron Gleason]

Put the idle bleeds back where you started and see what happens.
Doug

I'll do that

 

[Aron Gleason]

Based on his description, it does not sound like a tip-in issue.

No it's not a tip in issue

 

[68-500]

I believe 90% of carb issues are ignition caused. I have a tip in stumble. I have had time to work it out. But I am running manifold vacuum advance to get a quality idle. When I open the throttle vacuum drops timing decreases and it stumbles. My attempt will be to shorten centrifugal advance, limit vacuum advance. Hopefully then timing won’t fall off so fast thus eliminating stumbles. Could this apply in your situation?

 

[Aron Gleason]

I believe 90% of carb issues are ignition caused. I have a tip in stumble. I have had time to work it out. But I am running manifold vacuum advance to get a quality idle. When I open the throttle vacuum drops timing decreases and it stumbles. My attempt will be to shorten centrifugal advance, limit vacuum advance. Hopefully then timing won’t fall off so fast thus eliminating stumbles. Could this apply in your situation?

No, im running mechanical advance distributor. And ive messed with everything electrical and it still does it. And I dont have a tip in stumble, it stumbles when I go from cruise to wot to stab the throttle.

 

[Geoff 2]

Is the intake a dual plane or single plane?

 

[Aron Gleason]

Is the intake a dual plane or single plane?

Single plane M1 intake

 

[RemCharger]

I believe 90% of carb issues are ignition caused.

And conversely, 90% of ignition issues are carburetor caused.

 

[451Mopar]

Stumble is not high speed air bleeds unless they are way out of range. I would pull the carb apart and make sure all the passages are clean.
I had a new Holley carb with debris in the emulsion well of the metering block behind the jets.

 

[lewtot184]

After reading thru the OP's info i' m thinking fuel delivery.

 

[WS23U1]

As said it could be a lot of things. Try raising the fuel bowl levels 1/8 inch and see if it changed anything. Also check you fuel pressure, do this first.

 

[Aron Gleason]

As said it could be a lot of things. Try raising the fuel bowl levels 1/8 inch and see if it changed anything. Also check you fuel pressure, do this first.

Floats are half way up the sight glass. It has a consistent 6 lbs of fuel pressure and never drops

 

[lewtot184]

If you have a visible pressure gauge to watch and the pressure maintained 6psi during heavy throttle but the afr jumps 16-17:1 i'd think there's a restriction somewhere/gauge is wrong or calibration is way off.

Simple test is try another carb.

 

[Aron Gleason]

If you have a visible pressure gauge to watch and the pressure maintained 6psi during heavy throttle but the afr jumps 16-17:1 i'd think there's a restriction somewhere/gauge is wrong or calibration is way off.

Simple test is try another carb.

Its stumbled with 5 other carburetors in the past, from a 750 double pump carb to my current 950 double pump carb.

 

[lewtot184]

Its stumbled with 5 other carburetors in the past, from a 750 double pump carb to my current 950 double pump carb.

What fuel pump/ filter/ fuel lines, etc?

 

[Aron Gleason]

What fuel pump/ filter/ fuel lines, etc?

Holley black pump, aeromotive canister filter before the pump, then another filter after the pump. #10 fuel line from cell to pump all the way to pressure regulator. Return line is also #10.

 

[Geoff 2]

I would put the 750 carb back on.

 

[451Mopar]

Its stumbled with 5 other carburetors in the past, from a 750 double pump carb to my current 950 double pump carb.

How are the secondaries set up? I plug the power valve, and add the screw in jet extensions with the notched rear fuel bowl float. Then jet up about 4-6 steps from the front jets.