[Mag00]

I would need more specifics as to your testing methods. Motors will start with minimal compression, but if the timing chain jumped it will not. Find your timing marks on the side case and make sure the valves are opening at the proper time. You can check clearances at that time as well. Pay attention to spark as well. I'm not familiar with the flywheel on the bike, but on a briggs engine the keyway could sheer. Don't see how that could happen on a bike though. But check all the alignments.

I had a KX 125 that had spark and fuel and compression and would not start. To test the spark, I removed the boot and plugged in a spark plug and grounded it, had great spark. The problem was when putting it back into running config, it quit working. Just a simple plug wire had me perplexed for weeks.

Anyway, compression test and timing chain check would be a good spot to start with. While I would not rule out the cdi, it doesn't sound like the problem at this time. Document the procedures with pictures and notes.