912UL no spark

What is the voltage measured at the starter while the engine is cranking?
If it is less than 10 volts; try jumping a second battery to get the cranking speed up.

Take your module right where they are and put a gallon baggie of ice around them for 30 minutes. Then try a start. I would use full choke and crack the throttle. If it starts right up buy new ignition modules or if you have access to two other modules try them.