Electronic dash (Trailtech/Acewell) erratic reading?

[Goodtime]

Hey all. I am having an issue with the tach reading on my Trailtech Vapor. It is wrapped around the no spark plug lead. Works well at idle, and then goes all over the joint at higher RPM. Bounces up and down 1000-1500 RPM when cruising at a constant RPM. The manual says to add certain type of resistor. Before I go and do this, I wanted to know if anyone else has had the same problem and what you did to rectify it? I was thinking of running it directly to the stock RPM pick up but I am unsure of where it is on my bike ('92 900RR).

Any help will m be mucho appreciated!

[Hillsy]

I wired my Acewell straight into the tacho wire on my 00 zx9. Worked fine.

I have read you can wire in a resistor if the reading is jumpy - not sure what size though.

[Goodtime]

Any 900RR owners on here who can tell me where to locate said wire?

[Goodtime]

No one can tell me where the stock pick up for the tach reading is??

[Gix11]

My eyesight is shit, but looks like a y/g wire from the diagram: http://www.wiringsdiagrams.com/wp-content/uploads/2012/04/Honda-CBR900RR-Ignition-Diagrams.png

[Goodtime]

Legend mate!!