With lots of folks doing the baseline mods to their KLX250S, I'm sure there are those out there that really don't understand what is being done. Actually, the work is quite simple, just some basic hand tools and a fairshare of common sense will get y'all right through it.

To aid in your understanding of what we are doing, here is a tutorial on the Keihen CVK40 Carburetor and a parts diagram on the carb on our KLX250S. The operation of the CVK40 and CVK34 are almost identical. The difference main between between the two is the size of the bore. Obviously with a 40 mm bore, the CVK40 will flow more air fuel mixture than the CVK34. But if you want any throttle reponse that you don't need a sundial to measure it with, stay with the CVK34 on your KLX250S.


Kind of sit back, read a bit about what Todd and A16Tony have come up with, see how it affects the performance and you might even decide to do your own upgrades.