Model A

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Zenith Carburetor Float Details

Some thought provoking comments and information on carburetor float weights were recently posted by Darrel Beavers on a discussion.

Based on Darrel's experience rebuilding Zenith carburetors, some of the currently available reproduction floats are thinner and much lighter than originals. This discrepancy may lead to valve seating issues due to the inverted needle valve. This could then affect fuel level in the bowl and fuel consumption and carburetor performance.

Based on that discussion, I weighed a sample of my original A-9550 float collection, including 10 NOS Holley floats and several unmolested and undamaged used Zenith and Holley floats.

The table below shows the results of those measurements using a digital gram scale.

Model A
Holley NOS 30.6
Zenith used 31.3
Holley NOS 31.3
Holley NOS 31.3
Holley NOS 31.4
Holley NOS 31.4
Holley NOS 31.4
Holley used 31.4
Holley NOS 31.5
Zenith used 31.6
Holley NOS 31.7
Zenith used 31.8
Zenith used 31.8
Holley NOS 31.8
Holley NOS 31.8
Zenith used 31.9

from the data above, it is noted that the Zenith floats were all within 0.6 grams of each other, and the NOS Holley floats were within a range of 1.2 grams.

Notice in the pics above that the Zenith floats have different diameter weights (or none at all) riveted above the center of the float to bring them within weight specification.

My NOS Holley floats were all without added weights, but measured quite consistently overall.

Many thanks to Darrel Beavers for leading this discussion.

More related information on Ford Garage:

  1. For more Model A & B related information, use the Site Search box at the top or bottom of this page.
  2. Model A Zenith Carburetor Theory of Operation
  3. Model A Zenith Carburetor Numbering
  4. Model A & B Carburetor Jet Sizes & Flow Rates
  5. Model A Zenith Carburetor A-9545 Secondary Well Variations
  6. Model A Zenith Carburetor GAV Wrench
  7. Model B Zenith Carburetor Float Assembly Details

December 2015