[jhein]

Originally Posted by Baba O'Riley

Car is '71 Formula 400, with a just-rebuilt Rochester 7041263 and one of those “divorced choke thermostat” setups with the flat coiled spring.

I'm having problems with cold starts, it runs weak and rough at first with very heavy gas fumes. Sometimes the car only starts cold with the pedal floored – and a big bolt jammed in the choke butterfly so it’s all the way open.

Question -- the spiral spring on the choke thermostat, on a 7041263 -- does the looped end of the spring that attaches to the rod face the FRONT of the car, or the BACK? At present it's front-facing.

Just trying to make sure it's on right and eliminate this as a source of the trouble.

Thanks as always for your expertise.

So re-reading the OP, there are a couple things. The heavy gas fumes and the fact that you need to hold the accelerator wide open to start (like a flooded motor) would seem to suggest it's flooded. Also the fact that you have to prop open the choke valve would seem to indicate the same thing. That's letting in a lot more air and no fuel from the main metering system, leaning the whole thing out. I don't know enough about Qjets to know where to go from there but it seems like you have way too much fuel at startup and idle. So maybe has little to do with your choke operation? I'm sure someone who knows more will chime in soon.