I took my carb off to fool with it since it has been running pig rich. I changed the primary to jets to 68 and left the sec at 73. Tried to adjust the accelerator pump so there is .015 of clearance at full throttle (manually maxing out pump while at full throttle i have .015 of clearance) I cant get it to idle below 1200 rpm with the primary idle speed screw turned all the way out and it dies when coming toa stop. Any idea's?

 

with the cam in mine I have to keep the idle around 900 due to lope

 

if you are running a holley, replace th power valve. when they blow they run rich and will sometimes stall when stopping.

 

I replaced both power valve's with 3.5's

 

usually when choosing power valves they say to take a vaccum reading and cut the number in half and use that size valve

 

That's what i did. The last time a took a vac reading, the most i could get at idle was 7.5 in. I'm thinking i've got pressure on my accelerator pump or pumps. I've only got my sec opened about .020 so that should not be the problem. As far as it stalling when stopping it may be the bowls. I just took the carb off and tore it apart and then put it back on, i didnt do any tuning to it. It was getting too late. I'll check it out this evening. I have a buddy bringing me a regular holley 750 with mech secondarys tom. that runs good. If it runs good on mine with minor tweaking than i know my hp's circuits are way out of adjustment and i'll probably sell it.

 

Did you check or adjust the ilde transfer slot? If you filp the carb upside down you will see a tiny slot that gets covered by the throtle blades. You want to adjust the blades so that about 1/3 of the slot is exposed with the throttle closed. The adjustment is made via a small screw that is recessed on the baseplate on the underside of the carb.

 

Yea, that's what i was referring to in my last post when i said i had the secondary's opened .020. I have around 20 thousands of the idle transfer slot exposed on the underside of carb. As much as i have screwed with this carb over the last year and a half i should just buy the tool from holley that makes adjusting the secondarys accessable from the top of carb instead of having to remove it.