Force, Chrysler Marine 115-3301 Ignition - CDI Electronics

After receiving this unit I installed on my 1974 Chrysler outboard. The engine ranfine in idle for 15 minutes, then I applied trottle and the engine stalled out and would not start again. I send the unit back to CDI and received a replacement unit, I installed that unit and the engine would not start, I send the unit back to CDI and are now awaiting as to what do do next??? Dutchy