What engines will fit?

[thebig450es]

I've been looking for more power for my 400ex. Before i get to far, which engines will fit in a 400ex frame? I know a xr650 will, but will a 450r? I'd like an engine that can get above 50hp when modded a bit. thanks

[RIDEREDson]

Alot of them will with modifications. Im not sure of any "direct bolt on" engines. Unless you buy a hybrid frame. Maybe someone else knows...

[powermadd400ex]

Originally posted by RIDEREDson
Alot of them will with modifications. Im not sure of any "direct bolt on" engines. Unless you buy a hybrid frame. Maybe someone else knows...

yep pretty much.
go to the hybrid forum on here and they can tell you alot more than most of us in here can.