GT380 engine won't start

I have a 75 Suzuki GT380 that one fine morning would not start off the
kick or when I tried to run-start it. Instead when I popped the
clutch, the engine just hummed to a slow stop and never caught.

The points were replaced with a Boyer Bransen electronic ignition. I
took the cap off and could spin the ingition disc which did create a
nice pop out of the exhaust pipe. I'm told that I shouldn't be able
to spin the disc by hand but there is very little resistance.

Is there a pin or gear on that shaft to which the electronic ignition
is attached that has let go?

Anyone have any idea as to how challenging it is to remedy the
problem? Can I do it myself (I'm the village idiot)? Do I need a
profressional? Is there no hope and I should just find a new motor?

Any thoughts would be greatly appreciated..!

 

I appreciate the pointers!

There is a codder pin on the shaft that holds the ingnition system in
place. That is intact. It's what allows me to turn the ignition and
generate the pop. I presume it's something inside the motor along
that shaft that has broken off or detached.

An no, I am not an Arab. I do tan well for an Irishman though....