Holley 750 Brand New Issue's

[OutLawBiker]

1973 Road Runner
360 LA 60 over
340 X heads (fresh)
Erson Cam 480 lift 292 duration 107ctr
Edlebrock RPM Performer AIR MAX 7576 (NEW)
Holley 750 Dual feed Single pump Vacuum Secondaries Elec Choke (New)

Here's the issue-Carburation
Radical - (extremely sensitive) pedal. Quick response and the joy ends there.
After I back off the pedal she stays revved for quite a while (a few seconds) and with a very slow deceleration. It should respond as fast in both directions.
I notice when I hit the pedal the butterfly closes instead of opens-STRANGE
Does anyone know what creates this situation and the solution to it??

 

[hunt2elk]

Did you check to be certain that the throttle butterflies are not hanging up a bit on your base gasket?

 

[Frank Mopar]

Are you talking about the choke butterfly?

 

[OutLawBiker]

Did you check to be certain that the throttle butterflies are not hanging up a bit on your base gasket?

No, I haven't checked that yet-glad you mentioned it. I'm
going to do that right now. I'll hit you back and let you know
if that was my problem.

 

[OutLawBiker]

OK- I'm back after R and R the carb. It didn't seem like it was hanging up at the base. It is too early to fire her up -I have neighbors and it's only 7:35 am here on the west coast.
I'll start her up at 8:30 - 9:00 My R/R is really loud when the throttle sticks up in the high RPM range.

 

[turbine68rt]

Do you have sufficient return force with your spring setup?

 

[Daves69]

I notice when I hit the pedal the butterfly closes instead of opens-STRANGE

Is it the secondaries that are closing when you "hit the pedal"?

Is your throttle cable adjustment overriding your curb adjustment?

IMO, Pulling the primary throttle shaft back on an angle may not be helpful.

 

[OutLawBiker]

Is it the secondaries that are closing when you "hit the pedal"?

Is your throttle cable adjustment overriding your curb adjustment?

IMO, Pulling the primary throttle shaft back on an angle may not be helpful.

Hi ya,
No, it isn't the secondaries, it is the one on top you can see controlled by the lever on the choke.
The red plastic

 

[OutLawBiker]

While I was repositioning the throttle mount and cable to align with the carb in a straight line I recalled the machine shop I took my 340 X Heads to and this guy was a jerk. He didn't complete the job meaning he did NOT check, clean or even run a tread cleaner to the mounting holes and then charged me double-I truly don't know how some people sleep at nite.
In any event, all 12 holes were stripped out. I tried to compensate and obviously fell way short.
I ran a vacuum test and the new intake manifold leaks like a sieve. I need to heli-coil all 12 mounting holes. Does ANYONE know what size heli-coil to use??