yes, freeze the rotor with the light while idling with the can hooked and unhooked & see how far the rotor swings between the two. then at 2500 with the can plugged in, get the timing where it was when it was missing, then unplug the can/cap the carb nipple & twist the dist to get the timing back to the same #/same 2500 RPM & see if it misses or not.