The Stovebolt Site Forums The Shop Area Engine Shop Ongoing problem w/engine hesitation - 235

Folks -

I have a AD 47 3800 with a 235 from ~1960. I'm having ongoing trouble with low power and hesitation.

Okay, changed & flushed oil a couple of times, currently refilled with straight 30 wt. put a new set of plugs in, gapped to .035 checked timing and dwell. Timing is advanced about 10 degrees. Dwell is at 28, idle at 750...

Earlier, I had a severe hesitation problem. No power at all, had to really, slowly, feather the throttle to get any increase in RPM.

After the plugs and checks above, it is better, but not quite right. When I put my foot in it, I hear vacuum - a sucking sound, kinda like the economy. The engine hesitates slightly, then picks up RPM.

I don't have a vacuum gauge or compression gauge handy. I don't think I have compression issues - the truck turns over evenly and I do get a pretty good "pop" with the plugs out.

The idle mix screw on the carb is out ~2 turns, but it doesn't seem to have much affect on things until it is screwed to about 1 turn out - then the engine speed falls off and it dies.

Any ideas, what should I try next?

John

Your timing mark may not be accurate.
Your advance mechanism may be stuck.

Does the accelerator pump squirt (engine turned off) gas down the carb when you work the throttle linkage?

check your vacuum advance is it plugged or broken also if u have an aftermarket intake like a offenhauser u need to plum some coolant in to the bottom side of the intake