81 kz 750 ltd no spark

HI GUYS JAY HERE IM NEW TO SITE. I HAVE 81 KZ 750 H OWNED IT SINCE I WAS 15 YRS IM 30 NOW RODE IT ONE YEAR BERNT VALVE OUT. I JUST PICKED UP 77 650 RAN GOOD SO SWAPED ENGINE PUT ELECTRIC PICK UPS,STATOR,FLYWHEELE IN AND I DONT HAVE FIRE. I THINK IT IS THE IGNIGTER . I HAVE 12V TO COIL AND THE PICK UPS SEEM TO WORK I DID THE SCREW DRIVER TEST TO GET SPARK TO PLUG AND PASSED IT HAD GOOD SPARK BUT WONT SPARK WHEN CRANKED. I TEST THE 4 WIRE PLUG GOING TO PICKUPS AND HAD LOW VOLTAGE IN BOTH POWER WIRES BUT IM NOT SURE WHAT IT SUPOSED TO REED. THE OTHER PLUG OFF THE IGNIGTER WAS READIN 12V IN THE TO HOT LEADS . ANY HELP MUCH APPR