[mgreene]

Just started having the same problem with my SW tach in My Unique - 351C running a Davis Unified ignition system. Worked fine up until about a week ago, then started reading about 3000rpm too high and does not go back to zero when switch is off. Pulled the tach out of the dash and checked connections, stuck it back in and it seems to read OK for now. Seems like SW should do a recall/replacement...