The Stovebolt Site Forums The Shop Area Engine Shop 235 hesitating

Hi guys

I recently replaced the carburetor on my 235 with a new one. The old one had broken and missing parts but was rigged to "sort of" run like that, and it was leaking out all the gaskets. With the new one, it starts much much easilier, and generally runs better, but still hesitates if the gas pedal is pressed down quick to "rev" the engine. Runs and drives just fine however.
I have played with the idle speed and mixture screws to get it to run it's best, but it still does this. So I'm now ruling out the carb as the problem. The plugs and wires were replaced too, and the points are clean. Any suggestions on what it could be? My thought is a faulty vaccuum advance on the distributer...sound feasible?

I think you are on the right track. It's been pointed out by carb specialists here (CarbKing for example) that many carb problems are ignition problems. I would double check what you have done there and proceed to the carb then.

Mine did that (hesitated when goosed, but drove okay) when the 'spring' connector was not activating the accelerator pump correctly.

First don't assume your "new" carb is correct. If it is a Reman chances are about 1 in 4 that it is right. If it is a NOS it probably has been in storage many years & parts have dried up. If it is a salvage carb sprayed off with carb cleaner, who know's. First look down the throat of the carb with the engine shut off. Work the throttle from a closed position. You should see a squirt of gas go in the throat each time. If not or it is just a dribble, the accel pump is weak. If it is good try advancing the timing a little. You can do it at the octane selecter. Loosen the holdown bolt & turn the dist. CCW about two notches. You can check your vacuum advance by watching the dist as you accel the engine. The dist should turn when you rev up the engine. If that work's you will need to go into the carb. The float level could be wrong or the main jet might not be the right size for your engine. The fact that it starts & idles good is a real plus.