wanna build a hybrid

[spearman_929]

im looking to build a 07 400ex into something a lil more mx machine.i dont know what motor i want but does anyone have any good ideas for a low cost budget. please give me some ideas

[Punkmaster Flex]

CR250 for two strokes or CRF450 engines for four strokes. If you want to stay with a Honda engine I think they are both pretty good blocks.

Some put CR500s in their EX and they pull like crazy too but are a bit expensive too. :)

[416exman21]

go will cr500 2 stoke , cheap , and will be a death trap...lol