1971 TM 400

Today I brought home a 1971 TM 400. Clean bike with frame upgrades I can see. Looks like 2" or so added to the frame to raise the bike up. I got it to run for about 30 minutes and noticed it pulsating up and down on its own. I took the slide out and found out the needle was on top of the base plate under the spring. Fixed that and got excited and tried to kick start it up. No spark at all. Dead as a door nail. checked all the wiring and can't see anything out of place. I did find the coil wire as it comes out of the coil was rotted and the inner wire was exposed. Tried some electrical tape to insulate it but that didn't fix the issue. Can's understand why it ran and now nothing. I need help finding a coil and a CDI box I guess? Looked for those parts and nothing available. Is there an upgrade for this bike? Any suggestions or parts to be found are greatly appreciated.