nice grande. i have never seen a silver one in such good condition. First, take off the chain and belt covers. on one of these sides, there should be a little sticker with a number on it. the number is the speed at which that particualr moped is limited to. the grandescam in 20, 25, and 30 mph versions. yours is probably a 25. vespa had the limiter in the variator assembly. if you take it apart, you will see a bit of a big copper bushing sticking out under where the belt goes. this stops the variatorfrom making the front pully bigger than what is nessecary to go the speed limit labled. if you press in thebushing with an arbor press, to the point where it is flush with the rest of the assemble, you can probably squeeze another 5-10 mph out of the ped without effecting low end. This is the first mod i didwith my vespa grande and i highly recomend doing this. If you want, i may beable to post some pics or drawings of what i am talking about.