Honda 400ex engine in a motorcycle

Thanks to my good buddy ridesolo, I have been bitten by the large cc thumper engine swap bug. I have a cb550 project that would be the candidate frame, and a little thumper would sure make a neat little high torque around town terror. I almost had a deal made on a mt250 smoker motor, but that fell through, and maybe just as well. I may be able to make a deal on a 400ex atv motor, and was wondering if anyone on here has any experience with using one for a swap into a bike (very specific situation I know) I rode a 400ex when I was younger, and I know they are torque monsters, but I am just unsure on some things like sprocket offset ect.

I am well aware that it will in to way be a "bolt in" project and that motor mounts will need made this and that, but I was wondering if it has been done. I have seen a successful swap in of a XR600 engine in a 360 frame on here.

Thanks in advance!

Sounds like fun! http://www.dotheton.com/forum/index.php?topic=65541.0

jimmer said:

Sounds like fun! http://www.dotheton.com/forum/index.php?topic=65541.0

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yep looks like you have a neat one going on for sure!

It obviously won't be a drop in fit, but like with all things time and money can make it work. Sounds like it would be a fairly fun bike when finished. I nearly bought a crf450r wreck just for the motor to go into some future un-named project, but my wife reminded me how much infants cost...lol

*edited to add*
A quick Google search didn't show many 400ex swaps into anything. However there are several 600rr swaps into 400ex frames. So it looks like if you do this there won't be many out there that can say what will and won't work. Good luck though!

Reginmund said:

It obviously won't be a drop in fit, but like with all things time and money can make it work. Sounds like it would be a fairly fun bike when finished. I nearly bought a crf450r wreck just for the motor to go into some future un-named project, but my wife reminded me how much infants cost...lol

*edited to add*
A quick Google search didn't show many 400ex swaps into anything. However there are several 600rr swaps into 400ex frames. So it looks like if you do this there won't be many out there that can say what will and won't work. Good luck though!

Click to expand...

I have time, a little money, and access to a machine shop with a waterjet, so I can manage probably. I searched as well and didn't come up with anything. I do know a 400ex engine is a non kick start offshoot of of the popular xr400 Enduro. The deal fell through with the motor anyways. Turns out it had a cracked case, and I don't wanna go down that road