From the sounds of it you won't need a new starter as your engine is cranking, meaning your starter is turning the engine, it's most likely a spark problem, did you put the whire back on the dizzy??? Also is the condensor (little clyinder on the side of thee dizzy) hooked up, as these things can sometimes go on ya. Also check all your wiring, you could have accidently pulled a wire off the coil.

Cheers
Damo