OK, my turn again,
by now if I had spark and fuel and it still was a no-go, I would tow start it.
However,
Try this method of working backwards.
1. Remove spark plug, check gap.
2. Check for spark with lead on plug and earth spark plug on cylinder head
fin.
Lift the rear wheel, and give it one good hard pedal down as if you are
kick-starting a bike. If plug sparks at the tip, re-install the spark plug.
2a. If no spark, check Plug cap. I had to replace mine with a NGK Right Angle spark plug cap, (don't know the part No. though)
2b. Repalce lead anyway with Copper wire lead.
Check for spark again with new lead and plug cap
That's the electrical done from start of lead to end of plug tip.
If Spark, then go to Fuel.
If No Spark, go to Magneto and CDI.
But don't just replace the Magneto and CDI unless you do all the obove to.
That way you have a clean sweep out of sight out of kind type of thing of the electrics.
Fuel.
Remove Carby, AFTER Spark is all clear as explained above.
Remove fuel bowl, see if it was full or any fuel was in there.
If not, check fuel line and needle/seat where the fuel line plugs in.
There may be some grit.
If it had fuel in fuel bowl, re-fit carby.
Fuel is OK up to fuel bowl end.
Clutch adjustment, just go through the motions at the cable end. There should be no slack.
Can't say much about whats behind the clutch cover, never had one with problems ,yet.
By this time you probably flooded it trying to start and doing the other testings.
Then as last resort as I mentioned earlier,
Tow start,
and this will "flush out" the remaining cob-webs, and it ought to go.
Tow around the block or whatever until all reasonable doubt is undoubted if it still don't start.
Failing a tow start, then start the inspection process again the next day, so take a break, it's only a HT engine.
This time check for Head/Lower cylinder/Exhaust and Carby Gasket leaks etc.
Point is, dwelve deeper into the problem.
Tow again if all looks OK.
If it don't start still, I don't know what else from here, we may need pictures so we can see anything odd or unusual.