Looking into buying this blaster...

Any link to the stroker 240, or what exactly it entails?

BTW..i dont have a KDX anymore.

There was a guy I knew in my hometown that had a 90's blaster with a 240 stroker motor in it... To be honest I never askedhow he did it.I saw it take
off and it was pretty effin' quick... a lot faster then my old stocker (well it was stock at the time). If you want fast I would reccomend doing that because I can say I have seen first hand out fast they are! I doubt he was the only guy that had one as a set up, just google stroker motor yamaha blaster and see what comes up.
 
just look around on here there are some stroker-240 kits around. you're gonna need a new stroker crank, a 240 kit (probably gonna be a vitos) and have it ported to make it all happy