yz426 vs. yz450

[400exmx]

i currently have a yz426 motor in a 400ex frame i am looking at buying a new motor and leave my current motor for a back up. are the yz450 motors better or is the 4 speed terrible on a atv. i have talked to people who say that they love the 4 speed on a bike and i would think it would be nice on a mx track for a hybrid. i use my hybrid for 95% mx racing so would changing to a yz450 be bennificial thanks for any help

[ss440ex]

I rode a 4 speed yz450 in an atv frame , I like it better than the yz426 5 speed I had.

Less shifting and the engine seemed to have more torque.
Easier to ride.....my thought!

Now the lower engine mounts are different between the two...
The 450`s lower mounting bolt is .200 to the rear then the 426.

Just an FYI.

[usp4u]

IMO, now that i have a 4spd. i will never go back. i have a TC National yz450 and the thing literally could not have first gear. at most tracks i start in second, shift to third and leave it there.

[400exmx]

thanks for the help i think im going to go yz450 and use my motor for a back up