Fuel enters the Holley 1901 through the fuel inlet. When the fuel lowers and the float drops, the fuel valve pulls out of the seat and allows fuel to enter the float bowl. Once the float bowl fills to a specified amount the float raises and forces the float valve closed. A clip connecting the needle to the float keeps the needle from sticking in the seat.
There is a spring under the float (a very weak spring) that is there to keep the float from bouncing on rough roads. Install the spring so that the end that points up is toward the float.
How to Adjust the Holley 1901 Float
- Lift the float so that the needle seats. WARNING! Pressure on the viton tip can cause damage tot he tip and the carburetor will flood.
- Using a T scale, measure from the float bowl rim to the top of the float.
- To adjust, bend the tab that contacts the float needle. A small bend will go a long way.
- Both pontoons should be of equal height, but do NOT bend the pontoons. Bend the lever instead.