it's been sat about for years it is possible the piston rings may of stuck, carb will more than likely need a strip clean and reassemble, if it's a two stroke (sorry don't know this scooters engine type) the crankcase oil seals may of become hardened and no longer allow for crankcase pressure to exist, required for the transfer of fuel in a two stroke.
HT system working and no arching in the lead to the plug cap, plug cap arching. Plug no longer working under cylinder pressure.
Any safety switches which are fitted are they working, or have they become seized.
Basically you are going to have to systematically go through each system and check all parts for correct function.
Jaffa I bloody heard that. Pardon.
assumption is the mother of all f*** ups.