Disconnect kill switch first. Then test stator like jerry said. Manual helps. Jerry gave you good advice. He has extensive knowledge on these motors.
Mine turned out to be the kill switch under the dash was wired backwards. If yours has 4 terminals make sure its hooked up right.
You could use multimeter and test the kill switch.
Make sure the switch at the engine is being pressed in. This is to make sure it cant start in gear.
You can disconnect the kill switch at the motor or just pull the wires from the switch under the dash. Pulling the wires accomplishes what the switch does when the lanyard disconnects.
Once kill switch is ruled out then its stator or cdi packs. That website jerry linked will guide you.
Seloc/clymer manual has a procedure but it isnt that great in my brief exprience.
How do you know it doesnt have spark? Are you using a proper spark tester?
Its prob stator, kill circuit, or a bad cd pack. But like jerry said if its a cd pack and everything else is working properly, you at least get spark on 1 cylinder. Theres 2 packs and 3 cylinders. So its doubtful both are fried. Im guessing kill switch or stator. Test these first then post results.