im going mad in the garage, i ripped apart the motor to fix the valves and other stuff, put it back together and tried to time the ignition, it worked for a few attempts but then it just stopped, ive changed the ignition modul the pickup coil, tried another ignition coil, nothing, im running a 305tpi -90s machine with minor mods, have a 300+ accel racing ignition system and the distributor that followed in that kit. ive tried to connect it to just the system but it still wont spark, ive got volts to the ignition coil and the system but it just wont spark.

does anyone have any idea about what the problem could be?