Without reading through every post I'll start out from both scratch and basic. Testing steps up to you. Don't know what you have covered but my advise is to start from scratch.
Electrical....Compression....Fuel/Air....Exhaust
Timing... Remove the magneto cover. Remove spark plug. Rotate engine so the piston is at TDC. This can be checked by inserting something like a small screwdriver into the spark plug hole. Don't let the piston jam the tool. Look at the magnet/magneto. The magnet cut a ways need to be at 12:00 and 6:00 precisely. If not replace the magnet key. NEXT
Wire... Check wires making sure none are broken off from coil terminals. NEXT
Current..Isolate wires from coil from ANYTHING else on the bike. Using a test light, check to see if the coil is producing. A store bought or a home made test light will be fine.
How to make a very inexpensive test light. Buy a instrument cluster bulb. Bend both contact tabs down. Tabs will look like a loop of a paperclip. Find some very thin wire. A 22ga would be good. Wire from old ear buds, or old computer speakers works great. On one end split the two wires and strip the insulation off (enough to insert in loop and twist), twist wires. Insert one end into "A" and the other end into "B", twist each and tape if you like. On the other end split wire apart about a foot, and strip insulation back about 1" or so. Now you have a $0.50 test light.
Connect one wire from light to the black wire and the other to the blue wire, which one where makes no difference, white is not used and tape off. Place bulb where it will be easily seen while peddling (tape to tube if needed). Peddle to speed release clutch and look at bulb. If the coil is putting out the light will light up. No light replace coil. This test works great at night. NEXT
CDI Connect coil/magneto wires back up to the CDI. Make sure HIGH VOLTAGE plug wire is inserted into the CDI correctly. Get a length of wire, from a old extension/lamp cord is fine. Strip insulation from one end, enough to wrap around the spark plug base (just below the hex) a few times. If any left over twist around itself like a bread tie, and wrap with tape to secure wire. Insert plug into plug cap. Tape plug to tube in a manner you can see fire at the electrode. Remove a cover (clutch, main gear, coil/magneto cover) screw, and strip and wrap remaining end under screw and tighten. Peddle, release clutch and look for a strong spark. Weak spark can cause non start.