Do you mean the Ignition Coil Unit? Basically it sits above the rear wheel Below and in front of the petrol tank.
The HT lead from the top of the spark plug runs to the ICU, So just follow the cable back to the unit. Its powered directly by the battery, the coil is activated by the ECU (Electronic Control Unit) power stage on the basis of signals from the throttle unit, the engine speed (signal from speed sensor), the engine temperature, etc…
I have the Workshop Manual for that bike, It includes loads of fault finding help, Pictures, Part lists & wiring diagrams etc. If you would like a copy email me @ slippery.steve@ntlworld.com
Or look at my small guide I posted @ http://www.howtomendit.com/answers.php?id=143363
Best of luck!
Slippery Steve, June 2008
