Posts
4
Joined
4/19/2013
Location
Saint George, UT, USA
Edited Date/Time
11/13/2013 3:51pm
I have a 2005 CRF250R and want to drop the engine and put a 2000 CR500 in it. I think this would be sweet if I could do it depending on how much work it would be. Has anyone done anything like this? I found a kit on eBay which led me to their site with manuals showing how to do it and it doesn't look too bad (www.conversionparts500.com). Has anyone heard of or used this kit?
You can Google search and see photos of CR500 conversions that have broken in half.
mods since it was my first conversion and I wanted to make sure the "foundation" was done right.
Putting a CR500 engine into a gen 4 CRF250R frame is one of the more difficult conversions. In addition to cradle and
"Y' mods, the radiators, airbox, pipe and silencer mounts, coil and IC mounts and fuel tank all need to be modified or
relocated. The kit you're referring to has been used by several people with good results. If you have decent fab and
welding skills, you can pull it off. If not, I recommend you find somebody to do the work for you.
I'm building a similar conversion right now, but I'm putting a 2000 CR250 engine in mine.
There are a couple of CR500 specific websites with tons of helpful (as well as some useless), info:
CR500Riders.com
Banned CR500Riders.com
One thing's for sure, done right, this will be a fast bike.
dogger
My .02.
The Shop
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and suspension up to compensate. Comparing a 2008 CRF250R (gen 4), to a 2007 CR250R (gen 3), the rake, trail, ground
clearance and wheelbase are all pretty close. In fact, the CRF numbers are pretty much identical in all respects once you
replace the cradle with a gen 3 cradle with the kick downs and utilize a 22 mm offset triple clamp. Now both bikes have a
58.3 inch wheelbase, 13.3 inches of ground clearance and 27 degree rake. Throw in a re-valved steering stabilizer on the
08 and you greatly reduce any head shake tendencies under braking. I also had my suspension sprung and valved for
the 500 engine's unique (compared to the little CRF), power delivery. This is especially important with the shock. I also
run my chain adjusters all the way back to add a little extra wheelbase (59.5), to help with the light front wheel. Some of
these changes came about from testing and development, especially the shock, linkage, offset and wheelbase. I have to
admit, the bike scared the crap out of me the first few times I tried to put in some fast laps. I spent a lot of my time on the
gas cap still riding a wheelie. It's just like any race bike, you need to spend some time dialing it in - with this combination,
failure to do so could have some undesired consequences.
The gen 4 500 is still a handfull, but it is just as stable as any gen 3 I've ridden and turns better than all the others. The
CRF 250R frame is very compact and slimmer in the middle compared to the CR250 frame. This may not seem that
important, but you'll be glad you can move around and grip the bike easier when that 60+ hp comes on the pipe.
I still agree with CR500rider in that you should ride one before attempting the build. These bikes aren't for everone.
dogger
What kit are you using for your conversion and are you doing it yourself?
I will check more into those sites.
BTW, this bike is much lighter in the front end than my old '88 CR500 was, but I've had no significant problem riding it on the track. The engine is dead stock except for the ignition, and I'm using a YZ250 carb. It has an abrupt hit not far above idle that I'm getting used to which has almost looped my out on a couple of slow jumps--I think gearing down is the solution here (I'm currently 14-49 which is pretty high). I'm a vet rider who would be a fast C rider in the displacement categories.
Put my motor back into my steel frame, with a CR250 subframe and seat on it, and the twin chamber Showas on the front end. I really liked that combo.
is shorter (front to back of case), and wider than a CR500 engine. That means you have to clearance (grind), the right side
frame casting and kick down the frame rails to clear the right side case cover. A much easier conversion is a gen 5 (2010-
13 CRF250), or a gen 3 (2002-07), CR250.
I'll post some updates with pictures on my progress when I get the frame going. So far, I have the engine built, the wheels
done, subframe/airbox in progress, suspension ordered and a bunch of miscellaneous odds and ends.completed. I'm
using a new 2009 CRF 250R frame and replacing the cradle with a copy of the gen 3 CR250 cradle to gain access below
the case cover. I'll have to reshape the frame casting forward of the footpeg mount on the right side to clear the one case
cover bolt. The two mods combined will allow the engine to rotate down to a level orientation like OE.
dogger
Pit Row
I'm pretty sure you're right. The 500s are unique and bad ass, but most tracks these days don't allow them to "shine".
Throw in the extra punishment from a full moto and you kind of lose interest after a while.
"Why the CR500 motor over the KX 500"
Yes the KX 500 engine is a little newer and more refined in some respects, but if you can barely hang on to the lowly CR engine in these conversions, what's the point?
I actually had my CR engine "detuned" a bit. The cylinder was ported by Eric Gorr to reduce the hit and make the power more
manageable. Eric calls the tune "mo-betta". It still makes a ton of power, but now that power is easier to put down even when
traction isn't great. My CR makes most of it's power under 6000 rpm. With the motor loafing along, the only indication of the
speed is the wind roar in your ears and that corner that's coming up way fast. It's a unique experience.
dogger
I also had my 97 ported, the guy who did it knocked it out of the park. Took away the hit, the power was linear with more top and bottom. Just made it so much easier to ride, don't know why I haven't done it to my current motor. You really notice that power change on blue groove hardpack. No arm wrenching rocket launch to wear you out. If you DO want it, just whack the clutch lever once. All the hit you need.
We have updated our instructions on our website. We made sure all of the correct and helpful content exists. Let me know if you have any questions.
Good luck on your project!
-CP500
conversionparts500.com
And the swing arm has a 17mm pivot. Drilling the motor is in my future , I was wondering if anyone on this site has actually done this conversion with this motor & could recommend a solid method for making this work.
Thank you for any help. Cheers, Pat
Here is the URL http://www.conversionparts500.com/chassis-info.php
I hope this helps!
Several people have asked us to notify them when our 05-08 CRF450R kit was complete, so I thought I would share with everyone.
Here is the URL
http://www.conversionparts500.com/#!/~/category/id=5270709&offset=0&sor…
Let me know if you have any questions. I am happy to help.
Thank you,
CP500
www.conversionparts500.com
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