My buddy got 1996 Kawasaki Ninja ZX6R (600cc). He got a really great deal! While we we talking about the trade (traded for a 1982 Yamaha 750cc standard :^) the woman had mentioned that the Ninja ZX6R (600cc) was bored out into a 900cc. I thought WOW! That must be one great bike! but is it too good to be true? While moping in my jealousy, I was thinking about it and it sounds a little outrageous. We also have been talking and trying to figure this claim out together too. Is there a way to tell if it is a 900cc engine without taking apart the bike? He says he'll need to take apart the engine and need to buy new gaskets if we really want to be sure.

I rode it and honestly, it was as fast as mine, it's lowered so it feels a little faster and I think that they changed the gear ratio around to make the bike faster on it's top end (small gear in the rear and larger in the front). He said that his speedometer read 150mph at one point in time and he still had more to blow (Keep in mind that this is a 600cc from 1996) and the gear ratio was changed which would make a difference on the speedometer.

I rode behind him and I didn't see anything that he had that I didn't, I kept up just fine but, he could have been holding back (because of my ego and the fact that he's a great friend). Back to the question at hand. Can you bore out a 600cc sport bike engine to a 900cc and still have it perform the same as it would if it wasn't bored out??