Anybody know anything about swapping an XR 650 motor into a 400 EX chassis? Any pics of finished projects? I'm thinking about doing it myself because my little brother is getting a Raptor, and I am too used to eating his 300 EX for lunch(passing him in 3rd gear with the front wheels in the air), and I don't want to give up now!!! I would keep the 400 motor, but I don't want to use nitrous, or deviate from the stock bore too much. I like my machines to be reliable, and trouble-free. I am a competent welder, most of the time, and I am planning on an engineering major at Ohio State, and thought this might be a cool project to show off some of my skills. thnx a bunch

 

BADTRX400EX01,

sorry i cant help with the 650......

but what size jet do you run with the pro curcuit slip on???????????
i got the same pipe and im trying to get the jetting right..........
thanks for any help you can give....

 

Well, you see jetting is a very common horsepower increasing modification, and no good mechanics ever tell their secrets.......
yeah, right, bullsh!+ haha
lol, anyway, I'm up here in ohio, and my numbers may be a little different than yours-since you're down there in the warmer climate, and more humidity. I am running a 155 main jet, and I think the top-end is about spot-on. you might need a 152 due to the warmer air, which has less oxygen available in it. I am also running a 45 pilot, but it is WAY too rich. I am getting a 42 pilot sometime this week hopefully.......
You'll have to kind of play around with your fuel screw to set it just right.

 

it has a 152 in it.........
and its running too lean..........

the mechanic at our dealer looked at the plug and sugested a 155........

thanks again for the info.........

 

I don't know if this will be any help or not. . .but I know many Honda motors are interchangeable with honda frames. My buddy and I both put 350x motors in our 250x fmaes and they bolted up almost perfect witht eh exception of making some spacers and either shaving part of a motor mount off the frame or the motor. We were planning on making a bike the same way. . .a xr600 in either a 250x, 250r or 400 ex frame. . .but we ended up with a much bigger project. Anyway. . I'm pretty sure with somewhat little modification. . .you can make it work awesome. . .if you do. . please let me know how it works out. . .we still may do tha same someday. goodluck

 

In the ATV sport magazine they have a 650ex. They used the xr650 engine.... but I think they might have used the trx250r chasis.

 

which issue? Do they have a web site?

 

It is the latest issue I would assume... The magazine is my friends and he just got it the other day... and I don't think they have a website. I'll try to get more info tommorow when I see my friend I'll try to get that magazine from him.

 

That motor will bolt right in, you only need to modify the gas tank to accomidate the difference in height of the motor. You will not be able to run a head stay either. Look for a electric start model since that motor is a rear kick, you will have problems kicking through the fenders. I have seen one that they take the fenders off to start, or bump start all the time. You also have a push/pull carb on the stock 650 motors, so you will need to run a twist or do some throttle cable work and find a thumb to accomidate.

 

D@MN!! I didn't know it was that easy!!! And I know that a XR650 will eat a raptor so I might be doin this sometime soon. My brother decided against the raptor, cuz the starter clutches go out and its a $600 repair. Did honda ever make a liquid cooled 650 that was electric start? That would make a sweet dune machine, cuz even if its a little heavy, it has a whole lot of power!! Hey, you know that Service honda is making that CR250 motor kick forward. I wonder how we could adapt that so it could be liquid cooled?