Setting up the Carburetor on a Ford Model A copyright August 8, 2009 E. This article is about an easy way to check if the internal passageways in the carburetor are open or plugged. It's Auto Care and Restoration in Redding California. For a start, the screw closest to the block is the low speed idle. The model B carb has the fuel outlet pointing towards the radiator. Pull the throttle down to a fast idle right hand lever.
Pictured above is an end view showing the float components. Since this is a downdraft installation, the carburetor is mounted quite a bit higher on the engine. Turns out the complete pump wasn't for a Model-B either, but the body was. These parts are all similar but different than their Model A Zenith counterparts. Pictured above is the basic part numbers of the venturi and jets. No accelerator pump, not a lot of circuits and adjustments, but it works surprisingly well in practice. I found an aluminum carburetor inlet at Pierce Manifolds.
However the flange on the Model B manifold is rotated somewhere in the range of 7 degrees, compared to a Model A manifold. The numbers next to the jets is the jet orifice size as expressed in 0. Slowly turn the idle air mixture screw counter clockwise until the engine begins to stall and note the position. I have discovered that a new float from Bratton's and a new viton tip float valve from Bratton's usually work perfect with just one gasket under the valve. Model-A Carburetor Upgrade Model-A Carburetor Upgrade The stock Model-A carburetor is a very simple one-barrel updraft carburetor.
Firstly, look at the water pump at the front of the engine. The spark should be left in this position, fully retarded , for the rest of these steps. The detail drawings of the jets also tell the flow rates of each jet. While that's probably the best way to do it, I decided that since my Model-B motor had the boss for a mechanical fuel pump, I'd use one of those to be more in keeping with the vintage nature of the car. Renner to make the pump complete, and added the cost for the two shipments of core parts to him, it would have been cheaper, and a lot faster, to just buy a complete fuel pump without any core. The way I an looking at it then or the way it is when in the carb. Instead giving out the link to this web page would be appreciated.
I have encountered floats that were so molested that they were impossible to use. Without knowing where your jetting is your are just guessing. Says to bend float arm in necessary. Since I didn't like the looks of the lever arm on any of them, I decided to send one off to Renner's Corner in Manchester Michigan for a rebuild. Thanks for any and all advice. Push the spark advance all the way up left hand lever.
Unless I was going to open up the intake manifold or use a Model B manifold I would just use the Model A carburetor. The Model B carburetor input and output throats are also larger than the throats of the Model A carburetor. Can anyone tell me what height to adjust the float level to? However, the fuel line will require modification as the Model B carburetor's fuel inlet connection is on the end rather than the side. We offer a line of spare parts for these carbs. Also shown is the Zenith B style service carburetor expressly made and marketed for replacement use on the Model A. I had to make a little aluminum spacer at the top to extend it out a little from the bracket.
After installing the parts listed above the car now runs fine. It is best to never molest the float when trying to set the level. It was missing a couple of parts that I fabricated. Anyone know which is what and what a good initial setting would be? The table below shows the major differences between the regular and high altitude versions of the Model B carburetor. Wire Harnesses - Headlamp - Tail Lamp - Engine - Dash Made Right Here at Vintage! You should now be able to put the hand throttle lever all the way up without the engine tending to die.
Adjust the idle screw so that it hits the stop on the carburetor. Instrument Panels 1928-1931 - Panel Lamps - Hardware - Wiring Need technical help using our site? If it has an air filter, adjust it with the filter in place. Walt does not have complete quality control over his manufacturing suppliers. By the time I purchased the parts from Mr. Push the throttle all the way up. The idle screw will hold the idle at the speed you preferred, as set in step 7. Don't forget to visit the technical pages for your specific carburetor.