My '96 RM250 CDI started giving problems last summer. Used CDI units are a gamble, and not cheap. Have read about many street bikes being converted to GM High Energy Ignition (HEI). So I bought a used 7-pin module at the junk yard for $7.00, just for testing for this project, but I will buy a new 4 pin module now that I know it works. 4 pin has the advantage of dwell control. Rigged it to the existing pick-up coil, made a wiring harness and have temporarily rigged it (see the pics; will be a cleaner install in the next few days). Started on first kick. Nice crisp idle and throttle. Slight stumble in the mid range, which may be jetting, but might be an ignition advance problem. The CDI normally controls advance and HEI has no advance capability (done by the car's computer). I have read quite a bit about two strokes and learned they do not need the advance the way a four stroke does, and several earlier two strokes had fixed timing, no advance at all. I am going to slightly advance and retard the timing by trial and error, until I get it sounding good. The stator now sends AC voltage to a regulator/rectifier I bought online for $10. The output is 14 volts DC for the coil and HEI power supply. One of the best advantages of HEI is the readily available modules. Any auto parts store sells theme less than $20. If one goes bad, simply buy a replacement at O'reillys, Napa, Pep Boys or Auto Zone.