I have not done this, but I have ridden one and I know people who have done it . Yes honda makes that motor. It is currently availablein any motorcycle with a "L" designation. (I think). Remember, you will have to mount and run a coolant system now.I looked into this, I was going to sell my engine, carb, exhaust everything to a rental company that had blown the motor in a 400ex, its $2500 for a new 400ex motor, I was going to sell mine for $1800. Buy an older XR yank the motor and put it in mine. Problem is I could only afford an older bike w/ kick start and I am not into bump starting or taking off the fender every time I wan tto start. I will make one before too long, but it is going to be my hill shooter. I always wanted to have a 4stroke that could hang with 2 strokes on the hill. That motor has the potnetial to do it. Have you ever seen the bottom end of one of those motors? Can you say BURLY?

Good Luck

 

if you want to find a 650ex,
do a yahoo search on it........

 

Hmmmmmmmmm..................................... if its that easy, I'm thinking an xr650 in a 350x frame would be INSANE!!

 

when someone finishes post pics

 

For the kickstarting issue, just cut a notch out of the rear fender. As long as the frame isn't in the way it should be no problem.

I remember reading about a project quad in one of the mags, but don't remember which. It should be a fairly straightforward swap.

 

Does removing the choke help it that much?

 

Well, My EX pulls a wheelie in 4th gear on gravel, so you tell me!! I was kinda skeptical about it too, but now I would definitely do it again. The first two things a new 400EX owner should do, regardless of how old the bike is, is to take the swingarm bolt out and never-sieze it. Then put a 40 pilot jet in it to cure lean low-end.

 

First and foremost, I am curious how much power these 650 motors put out. I don't know what is realistic to expect... It would be an awesome swap IF it was powerful enough to warrant it. I'd like to be able to spank modded Raptors and DS's if I went through the trouble.

Second, I found a couple 'XRL' 650 bikes for sale on Cycle Trader. So both these bikes are electric start? One was a '94 model and I can't remember the other. Also, it sure didn't look liquid cooled...

EDIT - I just checked it out. I don't know how long the 'L' bikes have had electric start but I'd guess for some time. The XR is liquid cooled and kick start, the XRL is air cooled (my preference) and electric start. Sounds like a simple enough swap. Cheap EX + cheap XRL bike = cheap fun. [img]i/expressions/face-icon-small-smile.gif[/img] My question still remains on how much HP the 650 makes though.

 

Ride an XR 650 against a rappy or DS and you will have your answer.

 

HERE are a few pic's of a 650EX conversion. As you may have read in these posts it is NOT an easy swap. There are a lot of little things that need to be done to make it right.
These pic's are from a friend here in CA that races desert. He and his Dad have converted a few of these so they know all the tricks.
If your interested he will mod your frame and set you up with misc parts, liek oil cooler, and edelbrock carb for around $3K.