Demon Fuel Systems 4402020VE - Manual (Page 14)

14
Tuning the Vacuum Pod
Tuning the vacuum pod mainly involves spring changes to vary the opening rpm and rate. This is
achieved by using a tuning kit such as Demon Carburetion
™ part number 120083, which includes
springs that vary in the amount of pre-load and spring rate in order to fine-tune the carburetor for
every application.
The Quick-Change Pod allows for tuning with different springs without the need to remove the pod
body from the carburetor main body.
1. Using a wide bladed screwdriver or a coin (Fig. 20), remove the billet disk (color may vary from
picture) from the center of the pod lid. Once the disk is loose, lift the disk from the pod lid and
remove the spring.
2. Please note the O-ring that seals the disk to the pod top (Fig. 21).
3. Replace with a spring selected from the chart below and reinstall the disk (Fig. 22).
Figure 20 Figure 21 Figure 22
350 CID Engine 402 CID Engine
Spring Color RPM to Open RPM at Full Open RPM to Open RPM at Full Open
White --- --- --- ---
Yellow (short spring) 1620 5680 1410 4960
Yellow 1635 5750 1420 5020
Purple 1915 6950 1680 6050
Plain (std. spring) 2240 8160 1960 7130
Brown 2710 8750 2380 7650
Black 2720 Not fully open at max air flow 2390 Not fully open at max air flow