2.25 w/ a 2.5 cam, how advanced?

[scott]

thanks, andrew. i would time it by ear and the smooth sounding idle was happenning around 15-18 btdc. set at 6 and it idle rough but accelerates nicely.

[mechman]

I'd set at 6 btdc and check for an issue in the idle circuit of your carb. Old gas (or garbage in the fuel) may have partially clogged it. Check the accelerator pump circuit while you're at it, too - a sticking ball valve can cause rough idle as well. Too much advance will burn your valves...

Mech

[scott]

found part of the problem. while testing the adv action of the dizzy deck plate i notice it moving less than smothly. pulled it off and found a scratch about 5/16" long on the undeside where the eyelet for the ground wire was rubbing. i think this was mess'n with the adv returning to 6 btdc and slowing its advancing. still have a little popping but not nearly as much. lubed up the mechanincals in there too as they were pretty dry from the thorough cleaning i did when the motor was at the machinist's.