Most effectively, you should reduce the weight of your bike. That way the power that's already there will have less mass to push around. By following 3 thru 5 above, you'll make modest gains and that's really all that's feasible. Your 620 could be overbored to an 800cc with hi-comp pistons, some 900 cams and oversized valves and head work and ....and....and....
The age-old question is : How fast is your wallet?
Make a few tweaks (3-5 above) and after you get tired of the 620, upgrade to an 800 or 1000. [thumbsup]
The age-old question is : How fast is your wallet?
Make a few tweaks (3-5 above) and after you get tired of the 620, upgrade to an 800 or 1000. [thumbsup]