what is required CRF450r in 400ex frame

[CstMCgR]

What is required to do a CRF450 motor into a 400ex?? how hard is it to mod the frame for the motor and radiator? I have looked and its like 2000 dollars to send my motor to Curtis Sparks to have them do a 416 motor.....or you can turn around or can spend a little bit more and put the CRF motor in and have a bad *** quad.

[TC426EX]

Yeah, you can save alot of money if you build your engine mostly yourself. The most important work the engine builders do when building your engine is the head work. If you just sent your head for the port/flo/valve work and got a cam, you could save a ton of money. Then just get your cylinder bored locally, install an HD rod, and add the piston kit of bore and compression of your choice. If you did all that, youd be looking at spending about 1/2 or less than having sparks do your entire engine and it would be the same.

As far as doing the CRF conversion, I would reccomend leaving the frame modding to the pros. JB Racing, ATV 4-play and ECATV are all the front runners when it comes to doing that work. The frame needs to be modded mainly so the sprockets line up correctly. Realistically when all is said and done youre gonna be looking at probably 2500-3000 or even more to get the conversion done the right way depending on what you can score the engine for.

[CstMCgR]

Thanks for info......do you have information on how to contact or read about any of those companies??

[400exredrider]

you would probably be better off trading your 400 for a 450r and spending that 2500 to trade up

[CstMCgR]

If I could find someone interested....I would....

[TC426EX]

Originally posted by CstMCgR
Thanks for info......do you have information on how to contact or read about any of those companies??

JB Racing (Jody Bateman)

www.jbatvracing.com


East Coast ATV (Dave Gibson)

www.eastcoastatv.com


ATV Four-Play

http://atvfourplay.com/services/index.htm

If youre serious about doing this conversion, youre gonna have to call each of these places, or the one you choose and discuss the details with them personally over the phone. Its a big job and not something you can really browse the internet and click and buy... Ive dealt with all 3 of these companies and they will walk you through the whole process. I would call ATV Four Play and JB before ECATV because they are a bit cheaper than ECATV if I remember correctly....

[Rootar]

thanx ive been thinking about this for this summer either gonna be crf450 in my 400, sell 400 and get 450r, or sell 400 and get 250r rolling chassis for crf 450 motor. i think id rather keep the ex casue i like the feel of my ex over the the 450rs and 250rs that ive rode my 400 jsut feels like its fits the best

[johnnydufus]

what would be faster in a straight line? a 400ex with a stock crf450r motor or a stock 450r?

i like the feel of my 400ex too, if i am in that much of a need in power i would do the crf450 conversion. but i race xc and i dont need that much power in the trails... yet

[K_Fulk]

Originally posted by johnnydufus
what would be faster in a straight line? a 400ex with a stock crf450r motor or a stock 450r?

i like the feel of my 400ex too, if i am in that much of a need in power i would do the crf450 conversion. but i race xc and i dont need that much power in the trails... yet

A stock crf motor in a 400ex would walk all over a stock 450r.

The crf has a more radical cam, titanium vlaves, a better ignition not to mention having more compression and a few otehr things.

[JDiablo]

http://www.exriders.com/vbb/showthread.php?s=&threadid=90605&highlight=crf450

[rummerd]

Has anyone done this with an XR650 motor? Did a search and did not really come up with too much usefull info. Just the desert bike but no contact info. I have access to a kick assed desert racing 650 that really just sits, the thing just flies, I would think that that motor in an ex frame would have been a more popular swap.

[CstMCgR]

WOW!!!! thanks for the link...

[SHARPMACHINE]

rummerd,


A guy on here just did a 650 conversion. Do a search and you will find it, it looks very cool and relatively easy.

[rummerd]

the only 650 conversion I found on here besides the one for atvillistraded.com, was the one with the air cooled dual sport motor, which honestly, does not seem to be worth all the effort