Auto Meter tach in a 13B

[ulfelder]

I use an Auto Meter tach in my ITS RX-7. These tachs are set up for 8-cylinder engines; for others, you clip a wire or two. When I installed the tach, someone told me to clip the brown wire (which is what you do for most 6-cylinder engines).

I did so, and the tach reads funky. Basically, it indicates about two-thirds of my actual RPMs.

I put in a call to Auto Meter on this, but I had to leave a message and they're taking their own sweet time getting back to me. Anybody know which wire(s) I should clip?

[bill f]

I understand from an answer to MY question here about timing events on a rotary, that the tachometer should be wired as if it were a 4 cylinder.

Good racing.

Bill

[Festus E. Simkins]

If you set the MSD for a 4 cyl (and you do) it makes sense that the tach would be set for 4 cyl.

Drive well

[dickita15]

treat it like a 4 cylinder. i think that is right. each rotor has one compression per rev so two rotors, two pulses per rev, same as a 4 cylinder.
dick