The Ford Barn

TinCup · 11-01-2019, 01:23 PM

I have a very nice Zenith 1 that runs great at speed but tends to struggle to idle. I have gone through carb completely as I have done many others but have never found one that I could not adjust the idle air mixture. The passage is clear with the correct length air mixture needle driver. Turning it makes no difference in the idle of the carb whatsoever. No leaks around the manifold or gaskets to allow extra air into the circuit. It used to require more GAV adjustment than most but the correct #20 jet fixed that. Float height is spot on. My last thing to try is a different secondary well. There were 3 different wells and I have a version of all 3 so that is next on the list.

11-01-2019, 01:23 PM	#1
TinCup Senior Member Join Date: May 2010 Location: OKC / Tonkawa, Ok. Posts: 1,977	Stubborn Zenith I have a very nice Zenith 1 that runs great at speed but tends to struggle to idle. I have gone through carb completely as I have done many others but have never found one that I could not adjust the idle air mixture. The passage is clear with the correct length air mixture needle driver. Turning it makes no difference in the idle of the carb whatsoever. No leaks around the manifold or gaskets to allow extra air into the circuit. It used to require more GAV adjustment than most but the correct #20 jet fixed that. Float height is spot on. My last thing to try is a different secondary well. There were 3 different wells and I have a version of all 3 so that is next on the list. __________________ Oklahoma City Model A Restorers Group.