i just bought a 2000 Ds650 left over for very very cheap...never even has been started before...im already have like 500bucks in after market parts on the way to my house....and im not gonna start it untill i get all my parts on...CDI, exhaust, AC nerfs, handle bars..i wanna get differnt sprokets...what size does what??

 

what are you going to do for riding? littler front gears it down as does a larger back,

larger front higher top speed as does a smaller back, after that you have to decide what works for you. i run dune and gear down.