Any carb experts?

Any carb experts out there? What does it mean when you can take the idle mixture screws right out of a holley and it keeps running fine? I just rebuilt it and cleaned all the passageways, new gaskets, power valve and acc pump. Turning them in too far will kill the engine, but when I back them out, smoother, smoother, smooth, then it stays smooth even when when I'm holding the screws in my hand. What gives? It starts right up and runs good in the driveway (haven't had it to the lake yet).

I have had some race cars with Holleys on them and the idle screw did nothing to the motor untill it was screwed almost all the way in.

I have not tried taking it all the way out and running the car with it out.
sorry on help from me

I thought 1.5 turns out was standard on the idle screw? If taken all the way out, won't it bog down under a load? Need to adjust a carb on the water anyhow under load.

B

IIRC, adjusting the screw out too far just makes the engine mixture really rich.

I think I adjusted the idle mixture by 1) getting the idle speed about right; 2) turning the idle mixture screws in (leaning out the mixture) until the engine was running a little rough; 3) backing the mixture screws out just enough to smooth out the idle; and 4) readjusting the idle speed as necessary.

On the other hand, I have to confess that I had little luck trying to rebuild Holley four-barrels.

If it's a holley 4150 or 4160 4 barrell, you need a vaccum gauge to adjust these.

To use the gauge, turn both screws all the way until tight, back each screw out 1.5 turns.
With vaccum gauge connected, the engine running at idle or less than 700 rpm, turn one screw all the way, and turn it out slowly. You want to get the most vaccum possible, but with the needle not bouncing around.... steady... once done, repeat on the other side.

The mixture screws are only good for adjusting the engine between Idle and about 2500 RPM.s after that, it's a timing issue.

If the screws are all the way out, you probably have a leak somewhere.. or the carb is severly worn.

What type of boat or engine do you have? I just replaced my whole carb on my Nautique 84' with larger carb for the hungry 351 Ford... It runs much better now...had to redo a lot of things, fuel lines, timing, etc... but once done... it screams now...