MTFCA Forum

This is an easy one. Just installed a rebuilt Carb. The choke has to be completely open for engine to run. Any suggestions? Oh it is a Holly NH and is on my 24 Coupe. Center drain on bottom.
Ron

That's what I find with all my T's, a couple of turns with the choke closed and then the engine fires right up with the choke open, trying to close the choke any while the engine is running only over fuels it and stops.

Running too rich?

When cold crank once or twice with choke on. Then turn on switch and crank without choke to start. Some carburetors work best if mixture knob is opened a 1/4 turn initially and then closed once started. When warmed up no choke at all. Everyone is different so you have to experiment until you discover the best method for your car. I have 7 T's and none of them will start with the choke on but each one requires a slightly different procedure for cold starting.

frenesse wrote: ↑

Fri Aug 21, 2020 1:48 am

The choke has to be completely open for engine to run. Any suggestions?
Ron

With new rebuild the needle valve and seat are fresh, so make initial setting 3/4 to 1 turn counterclockwise from full closed clockwise on the carb adj. knob. That should work to start, a small amount of choke when cold, like two or three engine revolutions. Once warmed up, carb setting may need tweaking.

Requiring full choke to maintain running means fuel starved, carb setting adj. knob needs to be used.

Pull the throttle about 1/4 down. Spark all the way up and needle 1 1/4 open. As soon as it starts, pull the spark down about 3/4. You should only need to choke about 3 pulls up or just a short time if using a starter. If it quits soon, try opening, counter clockwise, the needle valve 1/4 turn and try again. If that doesn't help, you have a clog somewhere in the carburetor of fuel system. As soon as the engine starts, and keeps running, adjust the needle to the smoothest spot and push up on the throttle. You might need to retard the spark a bit to keep it idling smoothly. When the engine warms up adjust the idle screw to the slowest point it will continue to idle.
Norm

Norman
It worked. Thanks for the assist.
Ron

Think of the "choke" as a primer, closed for priming the engine, open for running.