With the engine off, look down the carb and mash the gas. Is there a long stream of gas or a quick squirt? I'm guessing the stream should last as long as the bog does. Bigger squirters dump the same volume of fuel in a shorter time compared to smaller squirters. You may need a bigger cam, the cam needs to be adjusted properly, and there are 2 holes on each cam for tuning. There should be lots of info on the net. I found this at
Car Craft
Q: What's the best way to tune the accelerator-pumpcircuit?
Holley Performance responds: The accelerator-pumpsystem consists of three main components: the pump diaphragm, the pumpcam, and the pump nozzle. This is the carburetor system that is mostresponsible for having good, crisp, off-idle throttle response. Itspurpose is to inject a certain amount of fuel down the throttle boreswhen the throttle is opened to smooth the transition between the idleand main circuits so that no stumble, hesitation, or sluggishness willbe evident during this transition phase.
The first adjustment to check is the clearance between the pumpoperating lever and the pump diaphragm cover's arm, at wide-openthrottle. This clearance should be around 0.015 inch. This ensures thatthe pump diaphragm is never stretched to its maximum limit at wide-openthrottle, which will cause premature pump failure. Next, make sure theaccelerator-pump arm is activated the moment that the throttle begins tomove, which ensures instantaneous pump response. These adjustments canbe made by simply turning the accelerator-pump adjusting screw locatedon the accelerator-pump arm together with the pump override spring andlocknut.
The amount of fuel delivered by one accelerator-pump stroke isdetermined by the pump's capacity and the profile of the pump cam. Thetime it takes for that fuel to be delivered is controlled by thepump-nozzle size. A larger pump nozzle delivers the fuel much soonerthan a smaller pump nozzle. During acceleration tests, if you noticethat the car first hesitates and then picks up, it's a sure bet thepump-nozzle size should be increased. A backfire (lean condition) onacceleration also calls for a larger pump-nozzle size. Conversely, ifoff-idle acceleration does not feel crisp or clean, the pump-nozzle sizemay need to be decreased. Holley accelerator-pump nozzles are stampedwith a number that indicates the drilled pump hole size. For example, apump nozzle stamped "35" has a 0.035-inch orifice. Pump nozzle sizes areavailable from 0.025 to 0.052 inch. Whenever a 0.040-inch or largeraccelerator-pump nozzle is installed, the "hollow" pump-nozzle screw (PN26-12) should also be used. This screw allows extra fuel to flow to thepump nozzle, assuring that the pump nozzle itself will be the limitingrestriction in the accelerator-pump fuel-supply system.
When changing the pump nozzle, it's best to jump three sizes. Forexample, if there's an offline hesitation with a No. 28 pump nozzle, trya No. 31 pump nozzle. If you must use a No. 37 (0.037-inch) or largerpump nozzle, then also use a 50cc pump. A 50cc accelerator-pumpconversion kit is available under Holley PN 20-11 when maximum pumpcapacity is desired.
Once nozzle size has been selected, the accelerator-pump system can befurther tailored with the pump cam. Holley offers an assortment ofdifferent pump cams, each with uniquely different lift and durationprofiles that are available under Holley PN 20-12. The cam profileaffects the movement of the accelerator-pump lever and, subsequently,the amount of fuel delivered by the pump nozzle.
Installing a pump cam is a simple matter of loosening one screw, placingthe new pump cam next to the throttle lever, and tightening it up. Thereare two or three numbered holes in each pump cam. Placing the screw inposition number 1 activates the accelerator pump a little early,allowing full use of the pump's capacity. Generally, vehicles thatnormally run at lower idle speeds (600 or 700 rpm) find this positionmore useful because they can have a good pump shot available comingright off this relatively low idle. Positions number 2 or 3 delay thepump action, relatively speaking. These two cam positions are good forengines that idle at 1,000 rpm or above. Repositioning the camcompensates for the extra throttle rotation required to maintain therelatively higher idle setting. Pump-arm adjustment and clearance shouldbe checked and verified each and every time the pump cam or pump-camposition is changed.
