Autolite 4300 Float
The Motorcraft 4300 float is a Nitrophyl type of float. These are solid floats but it is possible for these to absorb fuel over time.
When installing your float be sure to center each pontoon over the bowl so that they don’t rub the side of the carburetor. Both pontoons should be the same height.
Measure the float level as shown in the illustration. With the top upside down, measure from the gasket to the top of the float (technically the bottom). Different applications have different measurements. If you can’t find the measurement set it to 13/16″.
There is not float drop setting necessary.
There were some aftermarket brass floats used, but we seldom if ever see these.
Weigh your old float using a gram scale. 15 grams is the perfect weight for the 4300. a gram or two either way would be OK.
It is easy to get the 4300 & the 4350 floats mixed up, but they have distinct differences.
4300 float – 15 grams
4350 float – 14.5 grams
