we have nitrous kits here but no NOS mark only NX express exists here. the wear and tear on an engine is very flagrant if the mix isn't set right. for scooters i'd throw the idea of a dry shot system out the window since you wouldnt even begin to enjoy it before your engine has seizures. 70~80 kit engines are best for these things and only wet shots are recommended, for drag races only. if you're looking into everyday use you'd better be prepared for maintenance every week. i've had a bike with NX kit installed in it (a jog pro 90) i miss that bike it got stolen on xmas eve of 2006 never to be seen again. a shot gives you exactly 2~5seconds boost power but only activate when you reach you mid to top powerband this way you wont sacrefice your engine since the climb in powerband is normal (only 2 to 3 times faster), then as the effect falls off you're already in your top powerband and your engine should have recovered from the shot, a bigger jet is also good for these things as they provide cold fuel quicker to your engine, further reducing the possibility of piston head leak (where your piston's head melts and the aluminum flies all over the barrel).
ive had a mate with that problem on a kx250 . it melted the piston ring to the piston.. fast as fuck bike though.. :w00t: