big bore kit, its all bolt on! bigger carb, but you dont want to get a bigger carb until you have some other performance parts already on like an exhaust and performance air filter. hmmm what else, nology hot wire and coil, ummmm..... well, its not bolt on, but a port job to your cylinder, a port job gives you excellent power gains. If you were to buy a 240 big bore kit, def. get the cylinder ported, and youd have a really powerfull blaster.
either way, the only way id go with a 240 kit is if i planned to port it. a 200cc stock cylinder with a nice port job is faster than a blaster with a 240 big bore. Porting is where its at when you want big power gains!
ive heard great things about a company called flotech, i know they do port jobs, so if your interested in a port job talk to those guys and send them your cylinder.