Geoff.. before you worry about starting it.. go ahead and take that head off... it should have a lil copper gasket.. maybe not though if it is paper be very careful... I am sure your moped has a ass load of carbon on the piston.. you can buy some carb cleaner and knock that crap off.. also I would take ascrew driver and very gentlyscrap it off.. put the head back on torque to around 11 pounds.. you can also Take off your exhuase becuase I think that why it is stalling.. just a guess though.. its probly clogged .... the stalling seems like it is stalling after it warms up and the idel goes down... might be just bogged out becuase of the restriction. Take some snad paper and rub between your points a few times.. get a new plug wire and plug.. you want to use like an ngk5 or6 in them.
I found a 6 works pretty good for me. Also
on the carb.. (your gonna relaly learn to love there carbs.. ya right they are terrible) anyways. it probly has some crap on the filter.. I found the carbs dont get much trash ever actualy in them but it normaly has a ton inside the filter you can unscrew the thing and the filter is inside the carb just pops out. the coil and wire are the same (one peice) but you can get an 8mm plug wire.. pull the whole wire out of the coil
and skin the new wire foldering the elctrode over.. the 8m is the same size as the coil opening and you can use some greese to help shove it back into the coil.. it will fit snuggly and you wont have to worry with it falling out.
I dunno if any of this information really will help you.. but I would suggest look at the exhuast and the head first as they are the easiest.. Even if you dont solve your problem cealing the carbon... it wont hurt... I type so much i dont know if i said this ornot.. but unscrew your exhuast and try to run it and see if that helps .... should be a 1 1/4 screw.
.. let me know what you find out or any other questions. I love to trouble shoot these mopeds.. like i said I'm not a moped god..but i would like to be oneday.. ehhe