Holley Setting Float Level

Product Description

FUEL LEVEL (Float Level) – for Adjustable Needle & Seat Equipped Bowls:
0-80457SA & 0-1850SA:

Figure 8 Figure 9 The float(s) controls the fuel delivery, however if the float(s) are not properly adjusted a fuel starvation or a flooding affect could result. This operation is difficult to do accurately on a rough-idling vehicle.

1. Mechanical fuel pump, remove coil wire and crank engine over for 10 seconds to allow fuel bowls to fill. This procedure can prevent a power valve blow out. Reconnect coil wire when finished. Electric fuel pumps, let the fuel bowls fill in stages by turning the ignition on and then off, let fuel pump run for a few seconds at a time. This procedure can prevent the needle from being forced up at an angle not allowing the needle to seat properly.

2. Remove the sight plug from the fuel bowl and start the vehicle.

3. Loosen the lock screw at the top of the assembly.

4. Turn the adjusting nut while holding the screw in place until the fuel level is at the bottom of the sight plug hole even with the threads. A slight trickle can be seen at the threads. Turn the adjusting nut clockwise to lower the fuel level and counter-clockwise to raise the fuel level. Figure 10

5. Tighten the lock screw while holding the adjustment nut.

6. Replace the sight plug and finger tighten.

7. Flush the fuel bowl by revving the engine a few times with the transmission in the neutral.

8. Remove the sight plug to confirm your setting. A slight trickle should be seen at the threads. Adjust, if necessary.

9. Replace the sight plug and tighten.

Details:

To adjust the float level with the glass covered inspection hole type bowl, shut down the engine.

Loosen the lock screw on top of the fuel bowl just enough to allow you to turn the adjusting nut. Hold the screw in position with the
screwdriver.

Using a 5/8” wrench, turn the adjusting nut in the appropriate direction: Clockwise to lower float and counterclockwise to raise
float.

NOTE: Many customers attempt to adjust the float level down by turning the adjusting nut clockwise, only to see the fuel
level rise through the sight glass. This is due to the float being pushed down into the fuel, therefore displacing the
fuel to a higher level. You will find it easier to adjust the float levels, if you rev the engine slightly between
adjustments to evacuate the fuel.

Turn the adjusting nut in increments of 1/4 of a rotation.

Retighten the lock screw.


Restart the vehicle and observe the sight window.

SECONDARY FLOAT LEVELS:
Very little fuel is drawn out of the secondary fuel bowls during idle operation. This makes it a little tricky to set the proper float level with
the sight glasses. Many customers attempt to adjust the rear float level down by turning the adjusting nut clockwise, only to see the fuel
level rise through the sight glass. This is due to the float being pushed down into the fuel, therefore displacing the fuel to a higher level. With the open type sight bowl you can rock the car or boat to spill out any excess fuel in the bowl.

Once the floats have been set drive the vehicle or boat, making sure the secondaries open and recheck the float level.

Email us for a QUOTE or
more information about this product