mutley wrote:
Can anyone advise on 2-stroke engines? or is there a newsgroup dedicated to
them?

The Q is if the flywheel magneto may function perfectly when cold, but fail
when hot. I have a Stihl tool which starts and runs fine, but if it stalls
when hot refuses to start again. Fuel is OK, as is spark plug.

Possible condenser problem? Note, with small high-perormance
engines like this, the plug is critical - have you tried a
brand-new one? I've seen a few "plug is OK" jobs where there's
a problem with same.