Re: tachometer interchangeability
Perhaps I can help. The tack in a late, since the 80s motor, all work off the stator which gets its signal from one of the two leads, usually yellow-yellow on all single phase stators. This signal is taken from either one of these leads and provides the signal to the tachometer. The lead that goes to the tach is most frequently grey and is connected to one of these yellows comming from the stator. This grey lead that winds up, after passing through the harness, goes to the remote control on the boat and gets connected there to the tach. The tach connection also gets 12V and ground from the remote control and the signal lead we have been talking about. The selector on the tach is set for 2,3,4, or 6 cyl for proper reading of the tach. Locate the grey wire at the stator connection x-conn and follow it at the control assembly. This should be easy to find and is usually very universal. In summary the stator provides a pulse each time there is a spark produced which the tach interpolates as rpm. 2 cyl fires twice per rev, 3 cyc fires three times and so on.
