To all CR Hybrid builders

smokehouseman · Post by **smokehouseman** » 01:41 pm Apr 24 2013

I just picked up a 00 CR125 rolling chasis, I'm going to put my E series motor in it. To everyone that has did this build, what things would you do different and what parts worked best? I most likely won't be doing this until winter I don't want to be without a bike to ride this summer. So it will give me plenty of time to get the parts. Any help will be appreciated.

KarlP · Post by **KarlP** » 08:06 pm Apr 24 2013

I wished that I had bought a good pipe and modified it to fit. I used a pipe from a '96 CR 250 because that is what I had laying around. It was very ugly but ran reasonably well. I had to cut the end off a stock KDX pipe and weld it to the CR pipe to get it to fit.
I sold that bike to a guy up the street from me. He is still running around on it, having a great time. I raced enduros for three seasons on it.

I used the KDX airbox and boot, it fit into the subframe fine. I narrowed and drilled the cases on the KDX motor with a grinder and a hand drill. No problems.

Mine was an H series motor.

hadfield4wd · Post by **hadfield4wd** » 01:24 pm Apr 25 2013

Karl,

From your build it looks like you also clearanced the swingarm. Do you see any issue with taking it all out of the case? Just incase I want to put a cr motor back in.

Matt

KarlP · Post by **KarlP** » 08:49 pm Apr 25 2013

I don't think I changed the swingarm except to reduce the diameter on the RH side so it would fit in the space allowed by the KDX cases. I did shorten the bushing in the swingarm bearing by ~1/8" on the RH side.

The CR125 may be diffrent. I had a broken KDX motor and put it on the bench with the CR swingarm to see what had to be done.

hybridracing65 · Post by **hybridracing65** » 09:16 am Apr 30 2013

The pipe is probably the hardest thing you have to deal with but you need to use the kdx pipe and mod it to fit.
I used the kdx airboot, and the cr rads, you have to be creative with the plumbing.
My only complaint is i purchaed an ims oversized tank and have not got it fit yet. should have bought the clark tank i think.
Did not have any swingarm clearance issues but i used the 03 frame.

hadfield4wd · Post by **hadfield4wd** » 01:15 pm Apr 30 2013

hybridracing65 wrote:The pipe is probably the hardest thing you have to deal with but you need to use the kdx pipe and mod it to fit.

Why? Karlp used the cr pipe with a modification.

This is perfect timing for this thread. As soon as I finish the RM project with my son I'll be jumping on my hybrid build. The cylinder is already at powerseal.

smokehouseman · Post by **smokehouseman** » 07:53 pm Apr 30 2013

Karlp, you think the kdx pipe is better than the cr pipe you used? Anyone else which pipes did you use on your builds?

KarlP · Post by **KarlP** » 10:21 pm Apr 30 2013

I did not use THE cr pipe, I used a '96 cr pipe.I'm sure the '96 pipe was quite different than the '99 pipe. I also had to dent it here and there to clear a few things.

I would have rather used a KDX pipe. I got lucky in that it ran pretty good.

hybridracing65 · Post by **hybridracing65** » 07:32 am May 01 2013

I tried the cr 250 pipe as well.
The kdx does not run well at all with an 01 or 03 cr250 pipe. Pwr comes on then no mid range, no hit, just all overrev. It does run and you could ride it but not up to its potential. Pipe diameter is too big. Maybe an older pipe is better but its not worth it as its almost as easy to fit my KDX FMF pipe anyways.

hadfield4wd · Post by **hadfield4wd** » 08:45 am May 02 2013

Well I guess I'll see what I can do in order to get a kdx pipe to work. Quick one woods or desert? Also should I use a kdx silencer?

hybridracing65 · Post by **hybridracing65** » 09:54 am May 03 2013

If its a 220 then a desert. If its a 200 then the choice is yours, i run a desert. you can use the cr250 silencer!

dan_b · Post by **dan_b** » 06:00 pm May 07 2013

Hi all,

I'm new to the forum and just picked up a 2001 cr125 (I have a 2000 kdx 200 and if I don't find a deal on a 220 I will use the 200 for the swap) I was looking at another post elsewhere in which the cr frame was cut at the wishbone to clear the head and allow the motor to rotate down enough to clear the pipe. Anyone have other ideas about making enough clearance possibily dimpling the frame? The rest looks pretty straightforward.

Thanks, Dan

KarlP · Post by **KarlP** » 08:49 pm May 08 2013

I guess the choice is to cut the frame or modify the pipe. I think I would rather modify the pipe.

I don't think cutting the frame would be to feasible on the 250 frame. As I recall, I had to add about 2" to the pipe to get it to reach the cylinder. If the motor was moved forward that much it would probably cause radiator trouble.

You are working with the 125 frame.....

hadfield4wd · Post by **hadfield4wd** » 01:07 pm May 09 2013

KarlP wrote:I guess the choice is to cut the frame or modify the pipe. I think I would rather modify the pipe.

I don't think cutting the frame would be to feasible on the 250 frame. As I recall, I had to add about 2" to the pipe to get it to reach the cylinder. If the motor was moved forward that much it would probably cause radiator trouble.

You are working with the 125 frame.....

I agree with the modify frame or pipe comment. Also if you move the engine forward the you mess up the swing arm pivot. I have a 250 frame just like yours Karl. I will have to go with some air of custom pipe arrangement.

smokehouseman · Post by **smokehouseman** » 08:08 pm May 09 2013

Okay reading all of these posts, it's getting me thinking I might hurry up and do this instead of waiting until winter. How long did it take you guys that have done yours to do it. I'm getting anxious to do this but don't want to be without a bike to ride.

KarlP · Post by **KarlP** » 08:30 pm May 09 2013

It took a while, but I was not without a bike. I had a non-running motor and did all the fit up and fab work with it, then swapped to a good motor.

If you can find an old motor you'll be able to get a lot done. One of the first things I did was put that motor and the CR swingarm on the bench and get them fitted together.

smokehouseman · Post by **smokehouseman** » 08:44 pm May 09 2013

KarlP,
That's a good idea I'll see if I can find a old non running motor, cheap and mock everything up then all I would have to do is swap the motor when it's time.

hadfield4wd · Post by **hadfield4wd** » 08:46 am May 10 2013

What about a custom pipe? I assume the amount of pipe before the expansion I critical. The turns are basically just for the length right? So get the pipe you want. Cut off all the length before the expansion and use the same length pipe and do some custom bends to get the length you want ending in the expansion.

hadfield4wd · Post by **hadfield4wd** » 09:25 am May 10 2013

Using a mock up motor is a great idea. I've done it with car building, don't know why I didn't think of it here. Must be due to the fact that I can just carry the motor around. Mine is disassembled so I could just bolt it together and use it.

dan_b · Post by **dan_b** » 02:03 am May 11 2013

Karl,

The issue with the pipe is not as simple as to just extend the pipe. if the motor is not rotated forward enough there is not room for the pipe to have a path to the cylinder thru the very top of the wishbone. I did see another build with a newer chassis I think 03 and no notching of the frame was needed. Can anyone shed light on this?

dan_b

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