Accelerator Pump Lever Adjustment

Do not forget about the accelerator pump lever adjustment. For oval track use, the pump lever should be adjusted so there is no play in the pump linkage when he throttle is closed. This will assure that there will be no lean stumble when the carburetor comes off idle. Tuning an accelerator pump for maximum performance off the corner often involves reducing, rather than increasing, the pump volume and discharge rate.

Drag racing calls for a slightly different approach. For the hardest starting line launch with a foot brake, the pump lever override spring should be adjusted so that fuel starts to discharge through the nozzle at an engine speed lower than launch RPM. If a car leaves the starting line at 5000 RPM, the pump shot should begin at 4700-4800; an 1800 RPM launch calls for the accelerator pump shot starting at 1500. The key is to have no slop in the accelerator pump system at starting line RPM, so that the Shiny gold aluminum mist sprayers Factory pump shot is not "used up" below that RPM. Although adjusting the accelerator pump as described will create a lot of slop in the pump linkage at idle, (and may produce a stumble when driving in the pits) a car will leave harder. Drag cars equipped with a stick shift or transbrake, where starting line launch is accomplished with the carburetor wide open, requires adjusting like an oval track application.

Float Level Adjustment

When assembling a carburetor or reinstalling the fuel bowls, you need to adjust the float to be approximately 0.450" from the top of the bowl (in line with the bowl screw bosses when the bowl is upside down). This "dry" setting is to get you in the ball park. Recheck the float level with the engine running and the sight plugs out. Fuel should just wet the outside of the bowl as the fuel seeps out. On the secondary side, where the sight plug is lower, fuel level should be slightly higher. On Demon carburetors, the large, patented sight glass windows allow float level setting without having fuel escape from the float bowl. You can adjust the float level relative to the three cast-in marks next to the float window.

2022.03

Do not forget about the accelerator pump lever adjustment