400ex hybrid questions

[thebig450es]

I have an 2002 400ex which i love, but the power could be alot better, i looked into building my 400ex engine but it would take alot to get any real power, What engines would be an almost drop in ? Thanks

[250x_kyle]

no motor will be an almost drop in. its a simple as that.

[thebig450es]

are there any easier than others to do? 250r, cr500?

[woodsracer144]

all you need to go and do is get a better carb for that 400ex... find a 39 mm FCR for it and that thing will wake up... a 06+ 450r carb also helps...

[250x_kyle]

id have to say that yzf motors and crf motors would be easier then the two strokes because you dont have that retarded big expantion chamber in the exhaust to fit in. my yz hybrid fit up good.

[michaelopfer]

Yea, but you don't have to cut and weld your frame like a yzf hybrid.. ,my 250r/400ex hybrid works good....
plus, it's WAY cheaper to rebuild than any of them 4 pokes

[250x_kyle]

with the yzf motor i just took a little notch out of the frame so the intake had a better flow then bent a peice ot 1/8 inch steel in and tig welded it into the divit. then took some 1/8 inch wall one inch tube and made a gusset.

[thebig450es]

Keep the posts comming , ive been searching also trying to come up with the best option for me thanks

[00.400ex#55]

A cr500 engine fits great, infact the chain lines up perfect with 2 washers as spacers between the motor and the swingarm. But, it is deffinatly NOT an easy build. Mine has been 3 years in the making, it is all trial and error. There is also the occasional repair work, things do crack. It is not the motor mounts that crack however, it's everything else on the bike like rad mounts, intake, and the exhaust pipe is a pain to keep together. I would not recommend it if youre not planing on doing a **** load of work.

I don't have any experiance with other motors so thats all im going to say. Good luck