ATC 70 & 90 Ign blues

[splitman1]

Can anyone point me in the right direction please ??.I have an ATC 70 & 90,both were running sweetly after a long hibernation about 2 years.First the 90 lost its spark [got hard to start,then zilch] now the 70 has done the same,it was idling away warming up,then suddenly stopped [it had been backfiring a bit,but settled down again].I have tried all the obvious things points gap,new plugs,loose wires etc.Are they prone to blowing condensors or coils or something??.Im a long way away from good help,so any leads or hints much appreciated.
Thanks,Wayne

[Vealmonkey]

I would try looking at the grounds for the ignition system. On the atc70, it is a green wire that attaches at one of the coil mounting bolts. I believe on the atc90 the coil grounds to the frame at the coil mounting bolts without a seperate wire.

[blue27]

try new points, they will go bad with little to no warning.

[splitman1]

Thanks guys,I'll try both those ideas.My bike has a black and a green wire comming from the alternator.The green one wasnt connected to anything when I bought it,but bike ran fine with it disconected,where is it supposed to go ??could that be my earthing problem.The black wire goes straight to the condensor and coil,but Im not sure if its as it was originally??.Thanks,Wayne