So you spend $2,500 to have a motor built for your 650 that makes 80 hp and burns VP MR4.4 at $65 for a 5 gallon pail and has to be rebuilt every year? Sounds practical.
Nothing wrong with putting better suspension and brakes on a 650, as that doesn't compromise its usefulness or what you can do with it. Chasing big horsepower out of a 650 twin street bike is a silly endeavor, though. It still won't be as fast as a stock 600 and will now be less reliable to boot.
I agree , if you want a bike for the track then get a 600 and you can go as fast you want , and you don't need insurance.
The 650 strength is it's fuel economy , low end torque , low insurance cost and good looks , instead of ruining the strengths by making the fuel efficiency go down to achieve another 10-15 mph on the top end and half a second on the quarter mile , instead work on making the strengths better, like invest on its looks , suspension and brakes.
The 650 does a solid 130 mph on a straight lane with low wind , you really don't need to be going any faster than that , and it does the quarter on mile on low 12s which is enviable by most cars on the street ,all of this while doing an impressive hybrid-car comparable 50-55 mpg.
I have many people pointing in awe as I ride by and no passenger that has been on my bike has complained about the bike being too slow.
So why mess with a good thing?
Everything I consider getting a faster bike I think about the added fuel costs , added insurance costs , and more money to buy to begin with for the 1% of riding I do once in a while since I have not been to track.
One day I plan on taking my baby to the track to see how it does and maybe there it will be outshined but I keep up with other 600s super sports on group rides anyhow and I pass all of them on the turns since most of these guys only know how to go fast on a straight road and have no experience going around turns or are too scared to lean the bike.