If it is a UK bike you will have two restrictions. One is in the exhaust (engine end), you have to take the whole exhaust off, then drill out the restriction tube that you can see inside the exhaust. The other is the intake restrictor, you have to remove the carb ,then remove the inlet pipe which will have a plate on the end that you just have to pull off. That's it!! im no mechanic but i managed to do both recently on my NSR in a couple of hours, and it's well worth the effort!
JJ, September 2008