hi, about big bore, i have one. What can i say. It is rising performance, top speed, acceleration etc. but bike start to be "not to ride". The torque and power is so big that it is difficult to have two wheel on the ground. Till 3 gear you need to fight with throttle. (it is like in motocross when you have cr 500 ). There is a lot to do with big bore, i change exhaust for remus, ecm, crankshafts, lifters, it is good to buy new heads and progressive springs. If you put this all you will have 140 - 145 hp. Is it worth? NO. It is better to invest in good tires sport shock and riding skill improvement.