Depends on the year of manufacture.
The normal restrictions are in the ignition CDI unit and in the exhaust.
The CDi unit can be replaced or the restriction removed. To remove the restriction there are a couple of electronic components/links that have to be altered. Sometimes easier to buy a de-restricted unit.
The exhaust is the complicated bit. The full power version has a power-valve and associated control box and wiring, which the restricted version hasn't. The power valve changes the size of the exhaust port with reference to rev's. On the restricted version there is a fixed size port which gives smooth power up to about 6000 rpm and then tails off. The power valve opens up at this point and gives extra power in the upper rev range.
Don't be tempted to just remove the restriction without adding the power valve, the bike will not run properly, if at all, and you run the risk of engine damage due to misfires and fuel mixture problems.
The other consideration is the engine wear due to the extra power. You must anticipate having to rebuild the engine cylinder and piston every 8-10,000 miles as the extra power makes the engine wear much faster than in it's restricted form.
If you aren't sure what you're doing with this, it's not a straight-forward job and i would recommend using a reputable bike shop to do the work for you.
Karl, August 2007
