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have a 235 in my 53 1/2 ton. Yesterday replaced the car carb with a rebuilt truck 235 carb from Classic Parts. Difficult starting. Sputters and backfires. Got it going yesterday and had a nice idle for 10 minutes. This morning just sputters and I flooded it. Will check later. Any thoughts? Thanks, Scott

the new carb. may shoot more fuel from the accelerator pump than the old one did. If you usually pump the gas pedal before you start,,try not doing that,or not to the floor.If you have a manual choke,don't pull it fully closed to start. If the choke is automatic, it may need less tension on the bi-metal spring.

Thanks and will try.

Well this morning, 1/2 choke out, no gas pedal, turned over quickly but sputtered. Adjust the fast idle screw? thanks, Scott

maybe it is flooding out or the choke cable is messed up
I could start my 52 well below freezing with no choke at all
pat the pedal a couple of times and fired right up.. try it without pulling the choke out..pour a little gas in the carb, or try some starting fluid,at least it is firing, that is a plus.. dont try to make it to complicated..

play with the gas pedal, it can act as your fast idle

Float height, maybe...

Did the truck start hard before the carburetor was replaced?

Full choke- - - -crank until the engine fires without stepping on the gas pedal, then push the choke knob partway in as soon as the engine starts running. Most people don't use enough choke with a cold engine, or they leave it closed too long and flood. After a few starts you'll get a feel for how much to release the choke to get a smooth warmup. Within a minute or two (with a good heat riser) the engine should idle smoothly with little or no choke. An engine that starts cold with no choke is running WAY too rich!
Jerry

How did the engine start prior to changing the carburetor???

Weak ignition is the culprit as often (maybe more so) as a defective carburetor. If the ignition is defective, changing or adjusting the carburetor will not help the ignition. I have solved many "carburetor starting issues" by hooking a jumper cable from the ground terminal of the battery to a wire-brushed head bolt

Chokes were put on carburetors for a reason.....to aid in cold starting and help atomize the fuel prior to the engine acquiring normal temperature. As Jerry stated, an engine that will start cold without the aid of the choke is way too rich, and costing fuel economy, possibly even doing damage to the engine.

Carburetion 101 - there are three ways to improve the atomization of fuel: (1) heat, (2) air velocity, and (3) additional fuel i.e. choke.

Jon.

With the previous car carb truck fired right up. Checked the point gap- ok, 1 piston fires. Wondering if the air fuel mixture is off.. Will try again.

Choke all the way in- no choke- fired right up but sputtered. Gas pedal to floor. Sputtered for about 30 seconds then died. Thoughts? Thanks. Jerry, in moring will give full choke and start as you suggest above.

Tried this morning. No choke, Fired rtigt up but sputtered for 30 seconds then died. Gas pedal to floor.

Tried this morning. No choke, Fired rtigt up but sputtered for 30 seconds then died. Gas pedal to floor.

Sorry for the multiple posts. Didn't think original went through.

What do the spark plugs look like after it fails to stay running?

Why do I bother offering advice when the exact opposite starting procedure is attempted?
Jerry

Noticed that. Appreciate the advice. Pulled 1 plug and it was pretty black.

Black deposits (sooty) usually indicates that way too much fuel is being delivered. I suggest a complete rebuild of the carburetor by someone very familiar with your type of carburetor. That person could actually be you if you put enough time into learning it.
Carl

put the old one back on. If it works don't fix it. That way old, very good advice. I am an industrial mechanic, and that is almost a mantra at work.