Not a tri-five, but it is an old Chevy. Working on my sister's '63 1/2 ton pickup, 230 six cylinder, 1 bbl Rochester carb with manual choke.
Installed a new tank, put in new gas. I dissembled the carb, soaked all the parts in a gallon of carb cleaner. Sprayed all parts inside and out with aerosol carb cleaner spray, making sure to spray into all holes and openings. Blew everything with compressed air. Put in a new carb kit.
Put everything back together, pulled out the choke knob and it started right up running smooth at high idle. Let it warm up and pushed the choke in and it idled smoothly at 750 rpm.
Then I stepped on the gas pedal. The engine ran really rough with very little power. I figured it might be an ignition problem until I realized it ran smooth with choke cable out. I pulled the choke cable out again and it idled smoothly at 1200 rpm with the choke closed. So, at idle runs ok, with choke out it idles ok, but step on the gas and it runs terrible.
I guess I may have to take the carb back apart and clean it again. Before I did that I thought I would ask and see if anyone has any other suggestions.
If that carb is the same as a 55-57 (and I think it is) they are a little different than 2 and 4 barrels. The float level determines the mixture, so a low float level will give you a lean mixture and the choke will make it better.
So raise the float level (ignoring the specs) till you have a gray tail pipe. You may have other problems, but understanding the carb will help you get started.
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