[Fwilkinson]

I have had this same problem. Stalling while braking. I check all the normal things but still had stalling.
The fix I used was to lower the float level.
The fuel level is supposed to be set at 7/8” below the seam on the lower half of carburetor. I changed this by adding extra shims under the float valve to give me a 3/4” level of fuel in the bowl.
After this adjustment there was no more stalling at a stop when braking.
I think some people adjust to the fuel level even lower.
Fred