I just replaced the stock Hitachi 60 amp alternator on my Yanmar 3YM20 (Catalina 309) with a 14-pole Balmar 7-series 110 amp alternator. The tach readings appear to be different. The pulley on both alternators is the same. I have not been able to find out the number of poles in the original Hitachi alternator, and suspect the tachometer needs to be calibrated to the new unit, which must have a different number of poles. Does anyone know the number of poles in the Hitachi alternators? How about which setting (A - E) on the back of the tachometer (the factory setting for the Hitachi alternator is C)?