i wanna have more topend on my blaster. i got smaller tires than stock so it jumps outa the ground an then it just screams goin nowere.
so how many teeth should i have on my front an rear sprockets for good topend, around 80-90 mph.

 

I'd leave the rear sprocket alone.Change the front sprocket.Their cheaper.Try one tooth bigger maybe two bigger.If you go too big,you'll lose too much bottom end.I still don't think you'll hit 80mph,but you might.I wish I had a dime for every story about banshees that could do a 100mph and they really couldn't.Sure some will,but it takes more than just pipes.You are headed in the right direction.Porting makes a BIG difference in 2-strokes.Made a BIG difference in my banshee.

 

around 80-90 mph.

thats preaty fast