i have a 06 ltz 250 . just put a yoshi slip on plus a k @ n filter in stock air box used dyno jet kit for jetting. i am wondering if it makes a difference that i pulled out a 125 main and put the dyno jet 120 main in like it said. to me that dont make sense. it has awesome low end power . the air fuel seems to be adjusted right im out about 2 1/4 turns . im am just wondering if i am being robbed of top speed being that i put a smaller main in. i am 3 grooves down on the needle also. i am new to all this please any advise will help. like i said it just seems like i should get more top end is that true[img]i/expressions/face-icon-small-confused.gif[/img]

 

I bet he would like to know where to get an aftermarket airbox too... can anybody help him find one of these for a z250.