Ok....when I crack oopen the throttle, i get real bad hesitation. Gradual acceleration is good. Even when I crack it open from a higher rpm.....dead spot! Doesn't seem to have any misses, very decent idle at 800-900 rpm,and has plenty of power, except from a dead stop. Any suggestions?

My specs are:
Stock 396/325 block
Peanut heads redone
Crane 272 Hyd cam/lifters
Edelbrock performer manifold
Holley 4160 series 750 carb w/ vac secondaries
Hooker headers
Hei w/Proform upgrade
Timing set at 8 BTDC

Did you check your power valve? I'm not much of a fan for Holley Carbs.I like my carter AFB with electric choke . graemlins/beers.gif

Sounds like the accelerator pump might not be squirting.

TAke the air cleaner off so you can see what's going on and work the throttle by hand. You should see gas squirt into the primaries.

Pump was clogged on my 750 when I got it. Had to take it apart and blow air through it. Worked mint after that.

Tim.

My 750 just needed larger accelerator pump squirters. Take your air cleaner off and look in the carb and then open the throttle, you should see it squirt fuel out. The peice that the fuel comes out of is the "squirter" and should have a bolt going through the middle of it. Most people say too go up 3 sizes at a time and there will be a number on it, mine was a 31 and I ended up going too a 40 but my hesitation was so bad the car would die. If you know anyone with a holley, check with them too see if they have any you can try.

I agree with that, mine too had a bad bog off the line. I put bigger squirters in, ( you have to put a 50cc accelerator pump in to run the bigger squirters) difference was like night and day!!

Bigger squirters will fix the off-idle, but you may have other issues for when it bogs while cruising. Try the bigger squirters first and go from there.

Ctrain22,

Give these guys a try.

http://www.holley.com/TechService/TechServiceRequest.htm

Bubba

Tireburner - will all Holley's accept the 50cc pump? My 600 gives me similar problems and I want to increase the squirter size, but expect the pump to be next - right?

Guys, the 50cc pump need only be used when you get above a #40 squirter, which also comes with a special bolt.