2010 CRF250R / 2001 KDX220R Hybrid Build Thread
Posted: 09:08 pm Apr 05 2022
I've never exactly been the kind of person to let things be as they were. As time goes on and technology advances, I want some of the new with the nostalgia of the old. The General Lee, but getting 40MPG. A 1940's Willy's, but with working suspension.
So naturally, I looked at the 'dated' technology of our beloved KDX's and looked at remedying it. I'm not the first, and I'm sure I won't be the last to have the same thoughts and opinions.
I picked up the 2010 Honda CRF250R for $750 (which I overpaid for, but I couldn't find anything else so ) it was missing a lot more than I thought, but I drove three hours for it so I just cut my loses and took it.
I bought some Acerbis plastics for it so I had some motivation to work on it.
Then just yesterday I decided that I was going to try and tackle the build before the riding season really kicks off. I'm hoping to have the project done by mid May/June but we'll see what kind of wrenches get thrown in the way.
I tore the engine out of the KDX and placed it in the CRF's frame to see what kind of work I was looking at.
Obviously the "Y" of the frame will have to be cut and moved up in order to fit the exhaust, then all of the accompanying engine & exhaust mounts.
The good news - the CRF's swing arm and the KDX's engine case are (mostly) compatible. I will have to open up the hole in the engine to account for the CRF's swing arm shaft. I think that I will also take off about 3/32 of the engines width in order to run the stock CRF swing arm bushings.
KDX swing arm shaft in the CRF swing arm.
Bottom view, unmodified engine and swingarm. Almost perfect fitment width wise. The shaft and case clearance will be where I will have the issues.
It does look that I will have to provide some clearance on either the engine or the swing arm, as they are incredibly close (but surprisingly not binding). I think that I will shave a VERY small amount off of both the engine case, as well as the swing arm. I'm hoping that something around 1/16" will be enough clearance. I don't know if I can get away with a whole lot more than that.
I am still waiting on some parts, especially wheels. Those will be the big things keeping this project from moving forward.
So naturally, I looked at the 'dated' technology of our beloved KDX's and looked at remedying it. I'm not the first, and I'm sure I won't be the last to have the same thoughts and opinions.
I picked up the 2010 Honda CRF250R for $750 (which I overpaid for, but I couldn't find anything else so ) it was missing a lot more than I thought, but I drove three hours for it so I just cut my loses and took it.
I bought some Acerbis plastics for it so I had some motivation to work on it.
Then just yesterday I decided that I was going to try and tackle the build before the riding season really kicks off. I'm hoping to have the project done by mid May/June but we'll see what kind of wrenches get thrown in the way.
I tore the engine out of the KDX and placed it in the CRF's frame to see what kind of work I was looking at.
Obviously the "Y" of the frame will have to be cut and moved up in order to fit the exhaust, then all of the accompanying engine & exhaust mounts.
The good news - the CRF's swing arm and the KDX's engine case are (mostly) compatible. I will have to open up the hole in the engine to account for the CRF's swing arm shaft. I think that I will also take off about 3/32 of the engines width in order to run the stock CRF swing arm bushings.
KDX swing arm shaft in the CRF swing arm.
Bottom view, unmodified engine and swingarm. Almost perfect fitment width wise. The shaft and case clearance will be where I will have the issues.
It does look that I will have to provide some clearance on either the engine or the swing arm, as they are incredibly close (but surprisingly not binding). I think that I will shave a VERY small amount off of both the engine case, as well as the swing arm. I'm hoping that something around 1/16" will be enough clearance. I don't know if I can get away with a whole lot more than that.
I am still waiting on some parts, especially wheels. Those will be the big things keeping this project from moving forward.