yz400f in a 400ex

[EXlover60]

I've seen people on the internet put yz400f motors in a 400ex. does this motor make any more power or do they just do it to be different?
Thanks:confused:

[TampaBoy813]

I have one...its a lot of work and fab time...I like mine but I cant say I would do it again....

[ss440ex]

I have the 2001 yz 426.
Ex framed,
And there is a noticable all around power increase.