I own a 2000 400EX but I would much rather have a 250R. I have two options here. Trade or sale my EX and buy a 250R. Or I could just take my existing thumper engine out and put in a 250R engine. Is this at all possible? Would there be room for a radiator? Would this be a smarter thing to do than get a 10+ old 250R. I mean the chassis is newer and maybe even better than the R chassis. But I dont know. If you have any suggestion or answers to my questions, they would be greatly appreciated.Thanks

 

I would think it could be done fairly easily, Bracketry would be the only difficult part, but if you know someone who makes aluminum stuff, it should be easy. The frames are similar, and 400ex plastic will fit on a 250r frame with little mods.

 

yes it will i am currently trying to find a 250r engine to swap and when i went to a race 2 weeks ago i saw someone who did that. the only thing to worry about is engine mounts. your carb will work(there isn't really such a thing as a 2 or 4 stroke cab, just some work better in a 2 or 4 stroke) and a pipe mount. i'll let you no how mine comes out

 

I understand it can be done but is it better to just go with a 250R or is the EX chassis better? The 400EX carb will work on the R engine? It wont be too much carb for it, seems like it would flood it out or something. THanks

 

The advantages i see going with the EX chassis is that u can buy new one from the factory still it has round tubing instead of square which is suppose to be stronger and it has slightly longer suspension travel and ex plastic will fit and it is a fair bit cheaper than R plastic.

 

it can be done any conversion can be done but i believe an r chassis is as good or better than an ex chassis your biggest job will be fitting a pipe and mounting a radiator i suggest shopping for a 250r not hacking up a 2000 your cost for a complete machine wont be much more than the conversion will end up running

 

Hey whats up!! I agree with you about the conversion. Do you live in newport beach?? That is where i live.......if you live close by we should go riding!!
email me moinfar@rohan.sdsu.edu
laters Mike