EFI Bird, RPM needle, how to install it back?

[FTM 5]

So I'm messing around with the gauges, I have a spare set as well and I took that one to figure out how do I install the tacho needle back. I forgot what method I used, definitely not "push the needle back in on the 0 number mark" because that didn't work, so I did something else and only got miniscule moves from the needle when I'd rev the bike up, it would go up in small (100 or so) rpm increments. 

 

How does this contraption work and what is the correct way to install the needle back in the cluster? 

[superhawk996 2,504]

My guess would be to install it with the engine running at a known RPM so you can install the needle in the right position.  I did that on a car tach.

 

It's possible that you pushed it too far in and it's dragging/sticking or maybe pushing on the shaft damaged it.  I assume it's a stepper motor, I don't know exactly how they work, but you could google it if you want.  I don't know that knowing how it works will help much.

[Zero Knievel 1,334]

That or set the needle in enough to see how it moves but don’t fully seat it.  I don’t know what the flip side of a rheostat is, but basically, as the pulses from the RPM sensor increase, more current is allowed into the mechanism, moving the needle a prescribed amount on the dial.  I don’t see why removal of the needle would damage that.  I do know they have those stubs to stop the needle at zero, so perhaps the stub rotated too far without the needle and threw off the calibration?

[XXBirdSlapper 1,664]

You could also cover the tachometer with black tape.

[OMG 1,043]

On 2/20/2021 at 7:11 AM, FTM said:

How does this contraption work and what is the correct way to install the needle back in the cluster?

Could this be called a cluster fucked?

[DBLXX 2,312]

Fuster Clucked.