xr200 stuffed in a cr125...any info? thoughts?

[stormer94]

In my quest to NOT have to buy a $10,000 BBR screamer to play on, I've decided it would be great fun to try and stuff an xr200 engine in a cr125 frame.

I've been poking around and think I can scrounge an eraly 90's version of both bikes for around $1200 each. The 125 engine runs good, and I'm told I could sell it to some shifter kart guys for like $500-700. Leaving me with a total investment of about $1800.

I'm trying to build what I consider to be a good thumper for a 5'6" tall 155 pound 12 year old. He has been through the TTR125, and now has a KX100. A good race bike, but not as good for piddling and "billygoatin" like we do now and then.

I'm thinking the CR frame with about 15-18 4-stroke horsepower would be THEE ticket.

Technically, even the engine out of an old XL series bike would work to, now that I think about it. Doesn't have to be an XR200 donor.

I'm a good fabricator, and have any tool necessary to do the job, so I'm not afraid of the project. Just looking for some insight.

 

[CRX]

We have built a couple of them. They are excellent trail bikes. If you are interested, go to Google and search for CRX 280.

 

[stormer94]

CRX,

Was it you guys that built that bike?

 

[Rich Rohrich]

stormer - Get a hold of a copy of John Bradley's book "The Racing Motorcycle - A technical guide for constructors - Volume 1" http://www.eurospares.com/racebook.htm

It has a wealth of information on engine position and general frame/fab work. You'll probably also want to subscribe to Michael Moore's excellent frame builders e-mail list http://www.eurospares.com/frame.htm . Michael and the guys on the list have built some remarkable combinations and are very willing to help guide you through a new project.

 

[girlsbike]

I've got a 01 xr 200 and i have contemplated the very same thing.In no way could i afford to pay 10Gs for a bike to play on.I personally think it would be an excellent bike.Keep the forum posted it should make for good reading for many.
PS i would make sure the 125 i was getting was a steel frame,alot easier to weld and fabricate on.
good luck

 

[Jon K.]

I did a project of placing an XR200 engine in a KDX frame. Nothing fit and I had about 200 hours in the machine upon completion. And I am pretty good at this stuff!
Overall it was a good project and I am glad I did it, but be aware that this is not an endeavor to take lightly.
Just placing the carb and pipe was a nightmare!
I didn't even have room for the decompression system.
The horror!

 

[stormer94]

wfo74,

I've won 7 national championships racing lawn mowers, oval, road and drag. Been over 100mph on a mower, stuffed a 2hp Kawaskai engine in a barstool, made a 1978 Ford Granada into a pre-runner, and made a 1/2 scale garden tractor from scratch. Whipping up a motor mount and cradle should be gravy. :)

I think that you're likely to spend $3000 on bikes, get $1000 back by selling the CR engine, and spend $500-$1000 on new plastic, graphics, and parts to trick it back out. I think that, not including time, You should be able to whip this thing up for under $3000 and have a sweet machine. I'd use the BBR graphics to trick it out.

 

[Jon K.]

Yeah, well, I invented the internet. Neener neener neeeee-neeer.

 

[stormer94]

I thought that was Al Gore? :confused:

 

[atc3434`]

I would swing towards maybe an XR250 motor, more grunt. I guess it depends on if your looking for some power, or not. And another thing that would be funny, put the CR125 motor in a TTR125L frame. That would be hot, I'd ride it!

 

[sfc crash]

i was the first person to shoe-horn a 351 cleveland into a schwinn sting-ray with bannana seat and sissy bar. talk about a bear to kick over!:confused:

 

[keith500r]

just wait till I get my Segway... and a used cr125 motor