Opinions please

Oh no... it can still rotate and Spark, see it can even rotate somewhat less than engine speed at cranking because in such a scenario the chain driven by the crank just slipped and re settled on the cam gear setting the cam timing out enough not to run.

A lot of times they only finally slip in 2 ways "most of the time"... and that's under hard acceleration and more under deceleration, inertia takes over at a point when the chain and gear is just too loose and worn.

Hope that sheds some light.
But he says there is no spark at all. (Post #9) I understand if a gear slipped he would spark but not at the right time. Without a spark at all, either there is no signal to send a spark or there is a broken component to generate the spark, be it coil, wire or Dist. If the shaft of the dizzy is broken or the drive for it (timing gear) then no signal to generate a spark would be sent, thus no spark. To test that the dizzy is turning at all take the cap off and crank it and watch it spin. Unlikely, but an easy check.