Demon Fuel Systems 1563010VE - Manual (Page 8)

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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.
Figure 10
Final checking and adjustment must be made with the engine running and operating at the correct
fuel pressure (6
– 7.5 PSI). Final fuel level adjustments can be made before the engine reaches
operating temperature. A good initial setting is to have the fuel level in the sight window aligned with
the center of the cast-in rib, as illustrated by the arrow (Fig. 11).