Sputtering at low RPM

[NV Dave]

I'm trying to restore a 70 1600. I can't figure out the reason my car sputters when I first press down on the gas pedal. I can nurse the car up to 1500 RPM and it will run fine. I've checked the valve clearances, timing at 0-10 degrees, point gap, fuel filters, tried balancing the carbs. No luck. Also, I'm not able to advance the timing past 10 degress (assuming each hash mark is 5 degrees)with the dizzy turned as far it can go (clockwise). I've never had the dizzy out of the car, only a top end cleaning. Any suggestions?

[S Allen]

Is the car warmed up when it sputters? There are quite a few things that can cause sputtering. Is the air filter plugged with road grime? A vacum leak will cause problems, carbs too rich(float settings, stuck choke assembly, carb idle adjustment to mention a few) It does sound like you need to replace your dizzy(distributor) with a pre-smog dizzy(67.5 or earlier) or recurve the exisiting dizzy. I highly recommend one of Gary Boone's EI dizzy conversions but replacing with a non-smog dizzy is cheaper. There are actually two adjustments on the dizzys. The one you see at the base of the dizzy with the advance/retard markings. There is also an adjustment that can be made towards the back and to the front of the dizzy. There is a single bolt which attaches a slider plate. You can loosen that and gain a bit more fine tuning. I would still recommend replacing the dizzy with a pre-smog one.

Steve

[Minh]

You might have a vacuum leak at the shaft. this will cuase for bad idle or rich when running.

SUs can do that.

[LongBeach311]

I have the same problem and I have electronic ingition kit, but not the Dizzy ones. Low rpm kinda rough especially when I apply gas rapidly, but not after 2000 rpm.

When I turn off the engine, it diesels pretty bad...

Correct me if I am wrong:
backfires from carb = too lean
backfires from exhaust = too rich?