Originally Posted by hajime
I'm not sure what the problem is...
Neither am I, but we're all very sure that a spark problem and a starter problem are totally unrelated. Use the factory manual for checking the dizzy, coil, ignitor and their wiring. Jump the starter's solenoid with 12V, direct from the battery is quickest to see that the starter will work when it has adequate current.
Don't mess with solenoid contacts unless you're only hearing a loud heavy mechanical 'thunk' without the starter motor turning, that's the sign of solenoid working but contacts not making the connection to the starter's motor.