building a custom trailbike: Honda CRF chassis + XR250R engine

Just started a build-thread on ADVrider about the bike I'm building. 2005 CRF450R chassis with a '96+ XR250R engine.



Interesting project. I'll keep an eye on your progress. :cheers:

I'm very curious about the weight differences between the two engines, bathroom scales are accurate enough.

What little I've seen about such builds, they usually suggest the XR200 motor for it's smaller size. FWIW

Sorry Chuck, you'll have to google those engine weights. Didn't weigh the 450 before I parted it out. Can weigh my XR250 engine, but the info I found online says it should weigh about 74lbs. Curious what it'll end up weighing myself, minus the radiators and with all the changes I'm making.

Yeah, I really thought about using a CRF230 engine, but after taking some measurements, figured I could make the 250 work (ends up being plenty of room in the 450 chassis).

Yeah, I really thought about using a CRF230 engine, but after taking some measurements, figured I could make the 250 work (ends up being plenty of room in the 450 chassis).

Is there room for an XR400R engine? :>


Keep us posted, I love a good project thread.

Is there room for an XR400R engine? :>

Nope. I had an XR400 too, and there's just no way. At least not without major hacking, and at that point I'd rather just build a custom steel frame that uses all the CRF parts. Would also be a cool project, but decided that would still end up being too big and heavy, and too similar to my 650 to make sense.

the weight on my crf 450 with radiators was 75lbs (bath room scale)

Ah, thanks for posting. With/out coolant?

Damn dude, that is going to be sweet. Should see about bumpin it up to a 280 or 300. Rode with a guy once who had a newer XR250 and it was punched out to a 280 and had a shaved flywheel and everyone who rode it said it felt like a WR250.

Saw some of your other projects and this should look pretty fricken factory when your finished, cant wait to see more pics.

I'm in the process building my own frankenbike. My goal is to have a part from each major bike manufacturer..............but rollin with a steel frame. So far have Honda, yamaha, Suzuki, Husky parts, simply need something from Kawasaki and KTM to finish it out.

Is there room for an XR400R engine? :>

There was a video on youtube of a CRF with a XR440 power plant.

Yeah I've seen the pics and videos of that XR400 conversion too, and don't want to bag on anybody else's work, but...

that was with coolant

Great, thanks. So it should be about the same weight when it's all said and done.

Cool swap, crazy how big those air-cooled engines are though. Looks like it's actually bigger than the original 450 engine.

Personally, I'd want to find someone crazy enough to do the reverse swap of this: Swap a 450 engine into an XR200 or 100 Chassis. That would be a death machine :cheers:

When you finish the project and get all the details worked out, would you make a bike for me just like yours except use the XR250R engine that has electric start? I'd happily pay a pretty hefty sum to buy one of those :cheers::ride::p

How would we go about getting those e-start XR250 engines? Import them? Wonder how much that would cost. Would be pretty awesome, although at that point I think I'd probable prefer to just build a new chromoly main frame that uses all the CRF components.

holy cow that is so awesome! i want to ride it!

Thanks, ,me too.

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