adjusting a holley 750 dbl pumper

[Smashmix]

I have a holley that has been professionally rebuilt but for some reason doesnt like to stay running at times when you come to a stop anybody in ftworth area that knows a few things about holleys that doesnt mind helping me figure it out ill bring tbe beer lol

Thanks in advance rick
Feel free to call or text me
817-521-2245

["MrEd"]

Float is probably not set just right. Or the car needs more a/f adjustment.(air/fuel)

[Smashmix]

Im thinking tbe same but im not sure how to fix it or advance or retard the timing if need be

[beefed88]

I'm going to guess by things that you have posted that you are running this carb on a 302 with maybe stock heads?

[Vertnut]

That's a lot of carb for a small block. I would imagine even youtube would have some good Holley tips.

[Josh.0]

yup, watch a few of these

http://youtu.be/ge-mIk6nEYQ

[geartaker]

A guy I know with 85 was having kinda same problem a ended up just down sizing to a 600. It's a Holley thing about having to adjust them real often and that 750 would come out of adjustment it end up dumping to much fuel and flooding it.He hated the idea of a smaller Carb since he was one of those that thought bigger the carb the better. But he changed his mind after he swapped getting better MPG and performance. That 750 is to big for sbf and really to big stock headed sbf.

[Smashmix]

It's a 331 stroker it had an edelbrock 600 before but I'm thinking of doing a 408 stroker or 347 stroker I'm guessing it would do ok on either of those what's the biggest I could get away with on a 331 stroker

[Vertnut]

It's a 331 stroker it had an edelbrock 600 before but I'm thinking of doing a 408 stroker or 347 stroker I'm guessing it would do ok on either of those what's the biggest I could get away with on a 331 stroker

You'd be surprised what 600cfm will supply. It's like 350 cubic inches up to 6000 rpms. There are charts and tables that show recommended cfm based on cubic inches and RPM.

[Baron Von Crowder]

You'd be surprised what 600cfm will supply. It's like 350 cubic inches up to 6000 rpms. There are charts and tables that show recommended cfm based on cubic inches and RPM.

IIRC, a 302 calls for 500cfm by the charts.

[geartaker]

I'm not sure about the biggest you could go but my cousin had a 347 with a 600 and he had no problems

[Vertnut]

IIRC, a 302 calls for 500cfm by the charts.

Doesn't surprise me a bit. 30 years ago I was running a 700dbl pumper on a 428cj with a crazy cam and never had an issue. I know Holley used to make a 500 2bl manual choke carb that was a bad SOB. Simple to work on, and they were fine on modded small blocks.

[Baron Von Crowder]

Doesn't surprise me a bit. 30 years ago I was running a 700dbl pumper on a 428cj with a crazy cam and never had an issue. I know Holley used to make a 500 2bl manual choke carb that was a bad SOB. Simple to work on, and they were fine on modded small blocks.

My 69 has an electric choke holley 2brl. Im about to swap it for a 4brl, and hopefully can get some cash out of it.

[Smashmix]

Well I put the edelbrock 600 back on ill run it for a bit and see how it does thanks for all the advice guys its very much appreciated

[turbostang]

Your 750 can and will work fine, done it many times. If anything, your problem (symptoms) would be a lean condition that wouldn't go away no matter the jetting. (The signal across the boosters is weaker with a 'smaller engine' and a 'bigger carb' - bigger carbs move more air, not fuel till it's jetted to do so).

Carb's don't come out of adjustment, they get trash in them and THAT causes problems....along with people turning screws for no apparent reason.

Jacking the idle screws way in will cause ALL kinds of problems and render the air bleed screws nearly useless.

You can bring it by the shop and I can fix it if you'd like. It won't take long. (assuming there's nothing wrong - like blown power valves etc.)