rebuild ?

[400exrider26400]

how often do you need to rebuild these engines?
are they stronger than the new 450's?

[mccustomize]

it really just depends on how often and what type of riding you do. Generally most racers that run in a season put a new top end on these bikes once a year.

Compared to the 450's they do make good power, but a 450 is a broad torque and power curve, with a banshee you need to keep shifting to keep it in the powerband