Demon Fuel Systems 5563020GC - Manual (Page 7)

7
Priming the Carburetor
Fill the bowl through the vent tube until fuel is visible in the sight window. Depress the accelerator
pump levers once or twice until fuel is discharged from the pump discharge nozzles. On vehicles
equipped with electric fuel pumps, bump the pump switch on and off to fill the bowls a little at a time.
Avoid an abrupt surge of fuel into an empty carburetor. This can damage the floats and cause
flooding. Remember to check for leaks. The engine should now be ready to start with a minimal
amount of cold cranking.
Ladies and Gentlemen, Start Your Engines!
Get a helper. Unless your car can be started from the engine compartment, starting your engine for
the first time should always be performed with an assistant. A second set of eyes to watch for fuel
leaks can be invaluable. A generous amount of initial timing is also beneficial to ease starting. We find
18-24º of advance suitable for most performance applications.
Before engaging the ignition, depress the throttle fully and release once or twice. Now, attempt to
start the engine. If the engine does not fire under reasonable cranking, stop cranking and repeat the
process once again. Each engine may require a different number of throttle shots to ease starting.
Determine what is best for your engine.
Set the engine to a fast idle during the warm up period. If you change the adjustment of the idle
speed setting screw for the warm up period, make a note of the screw setting so that it may be
returned to its original position after warm up. This will prevent any drivability problems that could be
caused by incorrect butterfly position.
Allow the engine to achieve normal operating temperature before attempting final adjustments to the
idle speed or idle mixture settings. It is however, acceptable to make float level or fuel pressure
adjustments during the warm up period.
Preliminary Tuning and Adjustments
The following preliminary adjustments should be made prior to attempting to drive the vehicle.
Fuel Bowl / Float Level Adjustment
Although the float levels are preset during the assembly process, we recommend that they are
rechecked each time the fuel bowls are removed from the carburetor. To verify the ‘dry setting’,
simply invert the fuel bowl such that the weight of the float in the empty bowl rests against the needle
and seat in the closed position. The distance between the top of the float and the inside top of the fuel
bowl should measure approximately .400" to .500". A 13/32" or 7/16" drill bit is an excellent gauge for
measuring this distance (Fig. 10). Remember, this is only a provisional setting.
NOTE: Re-torque fuel bowl screws to 50 in./lbs. after the first 500 miles of operation.