Actually, there is a bolt-on kit out there to take it from 492cc up to 515cc with a new cylinder and piston. You can also go up to 600cc, but you have to bore the case a little. There is a hot cam available, and at least one brave soul has fitted one of the heads from a 1000cc buell Lightning to the blast motor.
There is a flattracker team claiming to get mid 50 hp out of the blast motor with headwork, cam, and the 515cc cylinder - supposed to be pretty stout for a single.
Stock the motor puts out 34hp at 6500rpm but it was somewhat detuned by Buell for its role as a beginner bike. Just swapping the pipe and re-jetting is supposed to free up 5 hp off the bat through the mid-range where the stock bike has a serious dip in its touque curve due to the restrictive exhaust.
There are two companies that build different rear-sets for the Blast - both cost $500 however.
There is a Corbin saddle availble for around $300.
Vance and Hines, Kerker, and Buell all offer a performance exhaust. White Bros. made one for awhile but quit due to quality issues apparently.
So, there are things that can be done. Anything major would be a one-off job for sure. Check out my profile. There is a picture of a one-off Blast by Crossroads Performance.
It has been chopped up pretty good, converted to chain drive, had the swing arm streched, up graded to 17" wheels, and the rest speaks for itself.
Sorry for the long post.<img src=icon_smile_big.gif border=0 align=middle>