weird cutting out problem

ok when it stumbled and didnt want to start i checked down the carb and it was getting fuel, thru the accelerator nozzle. Took awhile to start back up but finnaly did and it started up crappy tho but smoothed out and was able to go on my way. ran smooth for 30 minutes and started cutting out when i throttled it more. ran smooth intermittently but when i got off the off ramp it died at the stop. took awhile to start up again but did and i just limped it back home. The coil is an accel 40k volt and its somewhat old. The ignition box is sharing with the ballast resistor also. This problem is driving me F*&^*&%^&%^&&^ crazy!