If its wired backward +/- the timing normally will be drifting through the rpm.

 

not from my experience fritts, you are still reading the negative edge of the sine wave. The only difference is that the waveform is 180 degrees out of phase. The only time I experienced timing drift vs. Rpm was when the ignition output was configured wrong.

 

I think claudio can probably answer this better than me but I think haltech only reads the positive voltage signal of the waveform instead of the entire swing from positive to negative. I remembered it wasn't exactly 15 degrees off when wired backwards. It was more of around 12 degrees. I think The easiest way to test if the wire were backwards would be to convert it to positive edge and set trigger angle to 67. I think that would be the same.

 

That might be it, then. I didn't wire it in nor did I go out of my way to verify it was wired in correctly. You'd figure that it's supposed to be, right?

B

 

I asked Scott at Haltech and he said any of the following could cause drift.

Wrong trigger edge selected
VR sensor wired back to front
Incorrect ignition module/CDI edge setting
Trigger wheel moving (dont laugh - You would be surprised)
Certain Dial back timing light