How do I Adjust a Holley Carb 41504160 Float Level?

The float level on a 41504160 carburetor works like any other Holley carburetor by holding fuel within the carburetor and serving that fuel to the metering blocks. When the fuel level dips too low, the engine will starve for gas and run "lean," which may cause backfiring. If the fuel level raises above the correct level, flooding will occur, creating a "rich" condition within the engine, fouling the spark plugs and resulting in sluggish acceleration.

Instructions

1. Unscrew the fuel level sight port screw from the side of the fuel bowl.

2. Rock the car side-to-side while watching the sight hole. The fuel should trickle out. If it doesn't, the level is too low. If it spills out, the fuel level is too high.

3. Use a screw driver to unscrew the float valve adjustment screw (found on the top of the carburetor fuel bowl) two turns. Pry up the nut just below the screw to prepare for adjusting the float valve level.

4. Holding the screw in place, turn the adjustment nut clockwise to lower the fuel level, or counterclockwise to raise the level.

5. Watch the sight port hole and make adjustments to the nut until the fuel trickles out of the hole.

6. Reinstall the sight port screw and tighten it to the fuel bowl.

References

• HolleyPerformance: Float Adjustment Video Guide

Resources

• Holley: 4150/4160 Specs