i have a msd ignition on my 1980 ford and a adjustable timeing control. my truck runs fine for about 1 min to 5 mins then looses half of its spark, spudders. i put a different carb on it thinking it was a fuel related, but it didnt make any difference.

There is a round looking thing that looks like a capasitor that feeds power to the ignition, do you know what it is and how to test it.
msd says that if you are getting spark then the multiple spark discharge and adjustable timing components, then they workfine . got any ideas?

 

The capacitor is just for radio noise reduction. Only thing I can suggest is, if it all still plugs in, try the original set-up and see if the problem goes away.