Read this on another scooter forum.
Fellow buys a used Vespa.
A few days later, while running WOT for quite some time .....it dies.
He has not much $$, so hopes the fix is going to be simple.
He finds:
1) starter spins the engine much faster now, but no sign of starting.
2) just replaced the spark plug, but decides to check anyway.
Finds the plug end destroyed, with melted metal bits embedded in the plug.
Hopes a new plug will fix the problem.......
Stig