You can buy the exup servo eliminator from http://www.samannasystems.com/
or make one your self. One thing that also works it to attach a 7.5 or 10k ohm resistor to the white/red and black/red wires that attached to exup servo.
The exup servo eliminator emulates the servo motor and the computer does not show an error on the tach (if you tried removing the servo you know what I am talking about). You can also download wiring schematics and make your own servo "emulator". What seems to work is a resistor on the white/red and black/red wires. The computer only shows an error on the tach if I leave the bike "on" without the motor running. Aside from that no errors.