Oh, I see. As far as I know, the reg/rec that I bought, which is made for the Rotax 912 has better specs than the original part. That is to say, it is designed as an improvement on the original. Better cooling, better electronics, simpler wiring etc. for instance, it doesn't have that strange C wire. When the engine isn't running, the regulator isn't on. It's not slowly discharging the battery....