: CR125 Ignition instead of CR250 ?

08-30-2012, 09:58 AM
I just bought (Kinda accidentally) an 01 CR125 ignition off of ebay for cheap. From some research it looks like this should bolt onto the ESR adapter plate and work without any issues. It does have a different timing curve but you can plug the CR250 CDI right in from what I've read elsewhere. Has anyone else ran a 125 ignition?

08-31-2012, 05:04 PM
Bueller? Bueller?

atv fan 28
08-31-2012, 10:11 PM
Ive never heard of anyone running a complete CR125 ignition, but i do know alot guys run the 125 CDI on their CR250 ign.

09-02-2012, 10:47 PM
Well its on its way here so I'll get to check it out in a day or tow and know for sure.

09-14-2012, 10:51 AM
I got it in the mail. And it looks exactly like a CR250 one, so I should be good. Going to be experimenting with a friends bike as he is ordering an adapter plate and we will know for sure. I am waiting on a few other pieces to put together my second ATC so this will either end up on his bike or mine, in any case, it'll get a ride report.

09-14-2012, 09:35 PM
Sweet. Nice info if it works.

09-15-2012, 08:43 AM
the flywheels are clocked differantly.

here is a pic of a cr125 and a cr250 with the crank slots inline that shows the differance in the timing tabs


09-15-2012, 11:23 AM
Hmm, interesting. I hadn't compared mine side by side yet. Those are both 01s ?

09-17-2012, 06:58 AM
Yes the 00-01, plus the stator plate centering hole is different.

09-17-2012, 12:50 PM
Well maybe I bought a paper weight then. We'll see once I've had a chance to look at them further. I'm guessing you've been down this road already?

09-17-2012, 02:52 PM
Yes I own both the stators actually work on the cr500 because the center hole works out OK, you just have to move the rubber grommet on the wire harness.
The cr250 on a cr500 needs a bushing to take up the sizedifferencee
For you the esr plate is designed for the larger cr250 stator plate so you may have to enlarge the relief on the back side of the stator plate to properly center itself on the esr plate.
The flywheel probably could be used but you would have to not run a timing key and clock the flywheel to the correct position with a dial indicator and TDC. to much of a pain for 99% of the people out there.
If you buy a 00-01 flywheel then it works fine, thats what I do on my cr500

10-02-2012, 12:29 AM
Billy, I just did the same thing..The listing had it as a 2002 cr 250 ignition but I new by the cdi it looked like the 00-01 so I took a chance. Can I run a 00-01 cr 250 flywheel and have this work? Is the 125 stator and 250 stator different size where it mounts to the esr plate?

10-02-2012, 09:54 AM
A fly wheel change will fix the timing tab issues, I believe even the 98-99 cr250 flywheels will work along with the 00-01 but have not tested that.
I have not tried mounting the cr125 on a esr plate because I have a cr500 motor in my quad but I will say they are differant for sure.
The 2 bolt holes are the same its just the centering of the the stator on esr's plate that should have a raised lip to center the stator housing to the crank, the bolts are just to lock it in place not center it.
The cr125 stator housing will have a smaller hole so it should have material there that can be machined to the size of the cr250

10-02-2012, 11:08 AM
Work and other obligations have been kicking my ass, I haven't had a chance to really sit down and look at the differences between the two, but I think I should be able to make it work. I do actually have an old CR250 flywheel (from an analog system) that I can compare with the 01 CR250 one I have to possibly work-around the timing mark issue.

With regards to the stator plate, I put my 01 CR250 ignition on a CR500 one time also, and there was a shoulder on the backside of the stator plate I had to mill off, so when I took it off the 500 and put it back on the ESR plate, it didn't have the centering shoulder anymore like you mentioned, but with a little bit of care I was able to get it centered up around the crankshaft end by eye when it went back on my 250R and its worked fine since then, so perhaps the same thing can be done for the CR125 system.

10-02-2012, 12:47 PM
the cr250 on a cr500 requires machining also like you said but then it still does not center its self but you can use a heavy rubber o-ring or machine a bushing to make them work. or just use the cr125 housing that bolts on to the 500