yz crf 450 motor wanted for a hybrid 400ex

[joebabic]

hi i just got a nice 400ex roller that needs a motor so im looking in to a hybrid .whats the best way to do this and im looking to keep $$$$ bucks down so used parts are cool with me . last year i spent 2 much on my trx450 and dont want to do the same with 400ex frame i got it for 200 bucks so good start . my old lady will kill me if it starts to get out of hand .

[jcs003]

go 2-stroke. i am doing a 400ex chassis/250r motored hybrid and it is a fun build. not too complicated for a first hybrid.