should i swap

[geezy]

my buddy wrecked his new yz500 sold me da motor and all parts for 300 bucks should i put da motor in my 400ex n would it be more powerfull thanks alot, I HAVE DA TIME N MONEY TO DA DA SWAP

i would just to see how it turns out...but be aware that the motor may vibrate you and the bike apart...i am not sure what those motors are like, but some bike motors will do that...or so i hear