Problem with engine loping

[christian]

Ever since I got my slant window up and running I have not been able to get the engine running perfectly. I have been having a problem with the engine loping. By fine tuning the timing and setting plug gaps and point gaps I got it running better but still has a lope, sounds like a snare drum beating for a second, them off for a half second then back on, you get the picture. Distributor is a new unit from snyders, coil new all new wiring, carb is from a reputable rebuilder.

One odd thing I noticed is when I finally gave up fiddling with it, I shut off the gas valve to let it run dry, after a couple moments it started to run perfectly, smoother that my wife's 2012 Toyota. Then after about 15 seconds if sputtered and died. Could this have something to do with the problem. I'm guessing its carb related.

Another off thing is that the engine won't run with the idle adjustment screw more that 3/4 open.

Thanks for any input
Christian