Originally Posted by jaw22w
TDC has been verified. I just tried stiffer springs. It's getting better. Need stiffer springs yet. It seems that with the mech adv limited, the advance comes on quicker than before limiting. I'm slowly getting there.
The limit screw should have no effect on the starting point of mech advance only the end travel. One good not worn or stretched heavy spring and one light and the mechanical should not move till approx 900 rpm.
Vacuum advance needs a limit too, crane plate shown, second or third notch gives approx 14 Deg max vac advance or make one.
Adjustment screw on can only changes tip in not limit. Turn it all the way in carefully and then back out 7 turns after you install limiter plate, start from there. You need to change the base timing each time after installing or changing the notch on the limiter plate as the limiter moves the reclutor in relation to the pickup. I think these have a vacuum advance of almost 20 out of the box, that is why skip does not want you to go there, you will kill the motor with too much advance.
You can try and dial the idle/carb in with vacuum advance connected to manifold, turn the canister screw in all the way so that the 10-11"wg engine vacuum pulls the can all in, dont try and set the idle with the vacuum advance floating in the middle of its range with this cam.
Also again I think you are going to need more than a 72 jet on the primary.
If the thing wont idle than with less than 40 deg advance then you have other issues, distributor mods to mech and vacuum advance may not fix this just lessen the problem. Has this motor ever ran right?
Look closer at the carb/fuel/air delivery