how about just keeping the honda 400ex and other honda quads and if you want the quad faster just wait a little while longer and buy a brand new 450r engine, and drop that into your 400ex or an other honda quad. i think that would be a good idea. you get to keep your bike and you can save probally 5000 dollars by not buying the quad and just buy the engine. and i imagine that the 450r engine would fit perfectially in a 400ex frame.

 

No There is a guy here that did that to his 400ex and he had to do a fair share of modifiying the Frame and making mounts for the radiator .. but yeah that thing rips ..