hi i have a 1988 250x with a 14 tooth front sprocket and alot of other mods and i was wondering how to set up the tranny i want more top end should i just go up on the back sprocket or would that help any so any help would be great im running like 66-70 right now looking to go at least 75 how can i get it out of this bike!!

and where can i find an after market cdi box?? something like 1000 extra rpms or more.

 

in order to get more top speed. and i found this out on an adjustable drill press my first time...... the tranny needs a big gear, and the rear sprocket needs a small gear. so first threw 5 or 6? gears are going to be bigger than stock, i guess you could just change the last gear to be biggest but it would be a huge torque jump. just make the trans gears bigger....