I have a 1954 Mercury with a 256 with a factory 4bbl teapot carb that has been rebuilt by Carb Junkys. My problem started before the rebuild. It starts easy and idles great, and I can rev it about 1000 rpms before it boggs down and begins to backfire thru the carb. It has even caught fire and was able to put it out with a rag. I have changed the condensor, points, rotor and reset the timing. Plugs and wires are new last fall. I have played with the timing but nothing helps. Any suggestions? I have also developed a large hole in the muffler. Could that be the problem?
Thanks, Gary