Oh yeah, the link.....
http://www.scootertherapy.com/bosspage.htmlDoh!
I think it is well worth putting the clutch boss in. The part only cost me 35 or 40 dollars and made a world of difference. It allows the scooter to perform as it was originally intended, not restricted. I can't give you km/h references, but in mp/h I went from a top speed of 30 to somewhere between 40 and 45. You can convert those numbers to km/h for reference. The only two modifications I have done is the clutch boss and the cdi cut. I did them both at the same time so I don't know how much either modification alone would make. The top speed varies according to road conditions, incline or decline, and wind. I don't think the overall horsepower or torque is affected by these mods, so it still takes awhile to get up to speed. The consensus is that these two mods should be done first, and possibly changing the carburetor jet (which I have not done) before doing any other mods. Personally, these two mods are probably all I will do to my Agility 50 for now. Other options such as a big bore kit, different exhaust pipes, etc., all cost hundreds of dollars. If I were to do any more mods they would probably be clutch springs, rollers, stuff like that which is relatively inexpensive and gives some benefit.