rough running 1200 to 2000 rpm

[russbucket]

I have a 1952 century seamaid with the chrysler crown m47s-3 with dual updraft zeniths. Starts and idles fine. As I accelerate, at 1200 rpm it starts to run rough. Sounds like a miss. No back fire through the intake or after fire out the exhaust, just rough. After 2000 rpm, it runs great. Is there a mid range adjustment. I can only find idle and high speed.

thanks for help

 

[fastjeff]

That's a transition problem in the carb(s) when going from the idle circuits to the high speed circuits. Assuming the accelerator pumps are working, I'd look at the economizer circuit to see if it's not enrichening like it should.

Jeff