My NE50 was not starting w/ hot engine. I'd measured the coil, checked spark, everything ok. Many road tests and problem was getting worst.
Cleaned fuel tank, fuel lines, installed fuel filter, cleaned twice carb, checked compression, replaced spark plug, replaced CDI, checked CDI sensor on flywheel, recently it did'nt start at all even w/ cold engine


On your troubleshootings do not make the same mistake, think that a coil can have an intermittant internal short circuit.

Kind regards from Portugal.