hey. Im looking to drop a crf450 motor in a 400ex chassi. I know you have to do many mods. Im looking for any tips on what to do or watch out for when i do this. Can you hook up stock 400ex headlights to the crf motor? I gather you need a crf exaust for this mod? does any one know of a conversion kit for this swap? I know they make 1 for the 250x 350x conversion.

 

I have not done this swap. However you will need at the least a 450 wiring harness. The 450 hdlgt plugs may not fit the 400 lgts but the elements should be compatible. The exhaust will have to be custom fabbed as well as motor mts and intake stuff. You will also need the associated electronic parts-CDI, rectifier, ect and maybe starter electronics. Any reputable 4-stroke race shop is usually able to guide you if they sponsored race quads in the pre-production 450 mx wars-ie. before the YFZ450. E-bay is an excellent source for used parts and often have frames, motor mounts, pipes, airboxes, radiators, and such suited to this project- because someone else already did the work for you! I am not an expert, but I am bulding a 250R with a lot of 450R parts and understand. Hope this helps!

 

is vibration going to be a problem because it is a dirtbike engine?

 

<div class="FTQUOTE"><begin quote>Originally posted by: bigned1904

is vibration going to be a problem because it is a dirtbike engine?</end quote></div>

First thing I thought of! Is the dirt bike engine counterbalanced???

 

As I understand. A bike engine has no counterbalancer and transmits more engine feedback to the frame. They have been putting cr500 motors in quads for years and I guess people just accept it as part of the deal. Again- ask the people who started doing that before production 450's were available.