| Looking at the charts Skids attached (thanks Kev) it would appear that the 620ie is the weapon of choice(for me) which is what I had expected having compared specs. The older 600 engine can be got to similar levels by using the big bore kit and will have more mid range torque simply by dint of capacity effect-the 620 will rev easier at the top end.
What all this boils down to is if you can get a 620ie do so, all you need is cans and a modded airbox to go racing ( as well as the obvious removal of road kit, lockwiring, catch tray etc)
If you can only run to a 600 to start with don't worry since you can upgrade with the big bore and finish up with a competitive bike for less cost-it's your choice.
John |