I have a 2000 model cr 250 motor and was thinking of trying it in my 400 ex frame.Has anyone tried this and what are the downfalls.Thanks oz_400ex

 

Downfall: The CR motors have no counterbalancer. It would vibrate you and your bike to pieces.


-Matt

 

took the words right out of my mouth, i wouldnt even want to put the rubber mounts on there that everyone talks about doing, too much trouble, then again you could sell me the motor so i can make me a bad @$$ go kart lol

 

You guys have been reading too many magazines.

the vibration isn't that bad!

I've got a cr500 engine in an atc 250r .

a little vibration, but not bothersome

just plan on alot of work to get the pipe aligned in the frame

there is really not that much to it

 

Any pics?

 

no offense! know it all but the chasis on the atc is not the same as a 4 trax. the headset on the atc is very similar in design to a motorcycle and the forks also absorb this vibration everyone is talking about

 

I don't think the CR will vibrate that much. Think about it, the horrible CR500 problem.. Well, that's a 500cc piston moving up and down in there.. The 250cc wouldn't vibrate too much! Oz_400EX, I say do it. There's really only one way to find out if it will work or not.. Just do it! My 250R has a CR cylinder and head on it, and my FMF mounts right up. Good luck if you do it

 

hey lonestar get me some details on that cr jug project like any mods you have to do how much better it is what years of cr topends would work etc etc

 

Ohiowoodsracer, the only modification I did to it was a new TRX exhaust flange. The old one was worn out, and I decided I could make a TRX's work. I really like the jug. It wears out a little faster than the TRX, but it is seramic coated on the inside. I really like the option of boring out, or just ordering a new piston. It gives a little more midrange power too.

I would try to match years. My 89 250R has a new 89 jug. The way I see it.. If you can make stuff match, the better.

 

<< Think about it, the horrible CR500 problem.. Well, that's a 500cc piston moving up and down in there.. The 250cc wouldn't vibrate too much! >>



good point, but I still wouldnt want to take the chance of hurting my nice new frame.