I don't really know Terry. Back when my oldest boy started all there was quads with 2 stroke scooter motors in them. Now everything is fourstrokes and I will tell you that Yamaha is well ahead of pack with their chasis designs. Apex,DRR and some others have some really nice 2 stroke machines, but are they gonna riding 2 strokes when they get older? Prolly not! This the problem my oldest son is having. He's back on a 2 stroke this year.