Demon Fuel Systems 1563010VE - Manual (Page 9)

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Figure 11
Changing the float level is accomplished by loosening the locking screw and rotating the adjuster nut
on the top of the bowl (Fig. 12). To prevent fuel leakage during the course of adjustments, only loosen
the locking screw enough to allow rotation of the adjuster nut. Rotating the adjuster nut clockwise will
lower the float level setting; conversely, rotating the adjuster nut counterclockwise will raise the float
level setting.
Figure 12
It’s important to note that, although increased fuel levels are immediately visible in the sight glass,
lowered fuel levels are not. The excess fuel in the bowl must be consumed before the fuel level can
stabilize at the new lower setting. When lowering the float levels, allow the engine to run for a few
minutes, or gently rev the engine until enough fuel is used to establish the new lower setting. For this
reason, setting the floats a little low (.500" or more) during the ‘dry setting’ procedure, then raising
them to the correct operating levels with the engine running, will prevent flooding at start up. It will
also shorten the time necessary to reach the correct setting. Experimenting with float settings a little
above or below the startup setting is also acceptable.
Curb Idle Speed and Mixture Adjustments
Fine tuning of the idle speed and mixture must be done with the engine at or near operating
temperature. A good rule of thumb is to not attempt adjustments until the engine has achieved 160
degrees water temperature. Adjusting the engine cold will usually result in a rich mixture at normal
operating temperature. It is also helpful to use a tachometer and/or a vacuum gauge for setting the
idle speed and mixture.