Have you followed the installation instructions for removing the balast resistor? Have you checked for near batter voltage at coil (+), when reving? Has the Rev limiter been set per instructions, using 9V battery?
I really doubt it is advance spring related. That changes advance, not Rev limit.
This is my thought too.... the cutout for 1/2 seconds sounds like some of the cruder rev limiter actions. If the trigger was erratic (like a worn distributor) then I would expect the ignition to become ragged, not to fully cutout.