300ex jetting vs 250x jetting

[QuAdEr 317]

will a 300ex jet kit work for a 250x?

[cals400ex]

i don't know that i would use the needle for a 300ex in a 250x. it may work, but i don't know the difference in diameter and taper between the two needles. also, i don't know how the jetting from stock is on either bike. you could try it, but i probally wouldn't try it unless you can get the kit really cheap or free. i would just go buy individual keihin jets.