How do I make my 600 fazer faster?????

[stevierst]

Its all about valve opening timing. The more overlap you get, the more air/fuel you get in, and the bigger the bang (but only when the air speed onto/out of the cylinder reaches a higher velocity) hence higher revs.
Less overlap, but wider valve opening is making use of the slower air velocity at lower revs, producing more torque. Its a fine line, but its one that works. simplisticly complicated springs to mind!