My troubleshooting procedure is simple these days.
Disconnect everything.
Ohm the black magneto wire to a head bolt, it should read a dead short.
If not, check the ground tab on the magneto.
Note:
The new skyhawk CDI's have no white wire, ground is the lower connector but it has a wire from it to ground.
Old style mags with a white wire have a tab out of the mag that solders directly to the mag base and they can come loose, just hold it down and re-solder.
Ohm the magneto from the black and blue wire, 320-380 ohms is ideal, an open or dead short means a bad magneto if the wires are connected.
Ohm the CDI in the 10K-20K scale.
Red+ meter probe to CDI black wire.
Black- meter probe to the spark plug cap.
You should get about 6.9K ohms.
If not it could be a bad wire or cap.
Unscrew the plug wire at the cdi, use pliers or even cut it off and dig the junk out if need be and do the same test above again to the cable screw on the CDI.
If that works get a new wire and plug cap, if not you have a bad CDI.
If all of that is good there is only one thing left, the magnet.
That was indeed the problem with this repair on a new build with a 2014 gasbike.net front page engine kit.
When you pull the 4 bolts out of the magneto mount it should slam itself against the magnet, I mean to the point where it is hard to even get your first bolt in.
A weak magnet that lets you move the mag around pretty easily is not strong enough to create a spark which is what this repair had.
Magnet replaced, problem solved and my repair is done.
here are some images
