Information: I have a new 2003 model Aprilia RS125 and its GREAT! It was de-rigged after the initial run-in period and ive had 100mph [up-hill!!] out of it one one crazy occasion! The bike was happy about it, but i wasn´t!
Its more than fast enough for learning in standard kit. Pulls well from 6000rpm + in any gear. Red lines at 11,000rpm. A warning to any owners out there[or potential buyers], revving over 7,000rpm constantly seriously reduces fuel consumption! Ive found that around 6,000rpm & 60mph makes for the most effective use of the tank.
Also, if you want to keep your cylinder barrel for anything over 2 years DONT thrash the pants off the thing [6,000rpm+], before the engine temperature reaches 68-70c.
The reason for this beeing that you will overheat the piston rings and this will scrape the sides of the barrel from cylinder to oval shape within a few years! It will rattle like hell and refuse to pull properly from low gears. They dont need to be thrashed to run properly.
[I was told all this by a TT racer/engineer who works at my local garage and has had 2 strokes for years- thought some of you out there might find it helpfull!]