Model B float height

western77

western77

Senior Member
I have a Model B carb with the round float in it. What is the float height specs? I am having a hard time getting the engine to idle. It likes the stall when coming to a stop. It is a B engine with an A intake and exhaust. Thanks JB
 
I believe the Float Height is the same as a Model A, 5/8 in. If the float has the helper spring installed, remove it if you are using it with just gravity feed only, (i.e. No Fuel Pump). With the spring in place, the fuel level will be too low with just gravity feed.

Fuel lever is VERY CRITICAL to get a good idle and not having it stall when stopping.

Chris
 
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If you have a round float, you have a true 1932 B carb; these 32 carbs did not have the spring and lever helper to close off the float valve like the 33-34 carbs. You might try installing a larger compensating jet or raise the float level slightly; if you get the float level too high the gas will flow over the top of the main jet when you shut down and do not close the shut off valve on the gas tank.

Another thing that would be helpful is to increase the throat size of the A intake manifold to match the larger size of the B carb.

Ron
 
Ron in Quincy said:
Another thing that would be helpful is to increase the throat size of the A intake manifold to match the larger size of the B carb.
Ron
Click to expand...

I agree,

If you are using a stock Model A intake, you are really not gaining much unless you bore out the intake to the "B" Size.
 
Ironically, I'm having the same problem with the later "B" carb. I've run this particular carb for years with no problems. It did sit unused for a year but when I installed it on a new engine, it quits when coming up to a stop though when starting it idles ok. When I took it apart the float and splash shield (whatever it's called) was angled down, again all those years. BTW, no spring. When I leveled it, there was no difference. Pulling the idle jet showed no problems. I gave up and put another "B" carb and have not had problems. What could have happened to the first carb by not being used?
 
The FUEL level for a "B" carb is 1/2 to 5/8 inch below lip of the of bowl. Using the
Fuel sight level
tube.jpg
on the http://www.model-a.org/ site.

I found that it still takes some "fine tuning" to get the level just right.

JB
 
Thanks Guys for the help. I am going to go with the "B" intake and start at 1/2 inch below the bowl with a sight gage and go from there. It was running good in April and first part of May. Roger V, maybe summer gas in Michigan got us ????
 
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