Hi Jaffa, here are some ideas. Start with the simple checks before you get into the more complex stuff. Determine whether the problem is ignition or fuel related, and finally whether it's a mechanical issue.. Hot run it and let it die as he says, prime it 2-3 times:- does it restart, check for spark, try a new plug, check the kill switch is not shorting out(i believe most of those models had the safety brake so the kill switch has been re-routed to the throttle plate up front if it did):- does it restart, check flywheel to coil airgap, check the keyway.
When you try to restart after its hot does it spin freely or is the engine binding, like its overheated or partially seized. Is there oil in it?
I cant see it being anything toooo major. good lck and let us know how you get on.

Last edited by bigted; 22/03/14 11:15 AM. Reason: added info