Deal of a life time!! CR ignition

[Grande Huevos]

hey guys i just thought i would share my happiness with you! lol
I was browsing through craigslist adds lastnight while being bored and i came across this guy who was parting out his 2002 cr 250 dirtbike. I didnt figure he would part out the motor but what the heck its worth a shot right? Well im glad i did because i picked up a complete CR ignition in perfect working order and it all looks brand new. Guess what i paid??? ...........$75 I cant wait to install it and see what she does!!! By the way i need the adapter plate if anybody has one.

[mx91a]

Careful with the 2002 and up CR ignitions the keyway is cut into the flywheel about 12 degrees different relative to the pulse trigger than the 01 and earlier so you will need to run the flywheel without the key and offset it by hand and set the timing accordingly or have a custom adapter plate made that puts the pulse generator in the correct location.

[profab250R]

You may be able to find an offset keyway to set the timing according to the 01

[Grande Huevos]

Originally posted by mx91a
Careful with the 2002 and up CR ignitions the keyway is cut into the flywheel about 12 degrees different relative to the pulse trigger than the 01 and earlier so you will need to run the flywheel without the key and offset it by hand and set the timing accordingly or have a custom adapter plate made that puts the pulse generator in the correct location.

Dang thats no good! I always thought that the 01-03 were all compatible the way they are and 01 was just the best. How hard is it to offset it and adjust the timing? I have never messed with any of this stuff. Or Can you point me in the direction to get this custom adaptor plate? any help would be greatly appriciated! Thanks

[mx91a]

The 2000-2001 ignitions are the most desirable to swap onto the TRX for their digital CDI over the 99 and earlier ignitions. Unfortunately Honda totally redesigned the CR250 engine in 2002 and decided to go with electronic servo controlled exhaust valves amongst other (major) changes. In doing so they needed to modify the ignition to control and power the powervalves, hence the CDI with more connectors, need for a wire harness and other extras that were not present on the 00-01 ignitions. I believe it can be adapted to the TRX engine, leaving off the extras that were needed for the powervalve. The main problem lies in the flywheel, with the 02 and up having the key way cut 12 degrees off of the 01 and earlier. This must have been due to either a change in the location of the keyway in the crank or change in the orientation of the stator mounting plate onto the engine. Here is where this difference was discovered:

http://www.ekartingnews.com/viewtopic.php?t=66607&postdays=0&postorder=asc&start=60

It LOOKS like the 02-up stator plates have the pulse generator in the same location relative to the stator mounting plate and holes as the 01 and earlier but it is tough to verify without having them side by side. This means that when you fit an 02 ignition to the TRX engine with an adapter plate designed for an 00-01 ignition the timing will be retarded by 12 degrees. Here is an older thread where someone tried to fit an 02 to his TRX and it exhibited all the problems of a severely retarded ignition timing (hard starding, extremely hot exhaust, no bottom end power):

http://www.exriders.com/vbb/showthread.php?s=&threadid=446502

The fix should not be too difficult and there are several options you can go with. I'm not sure if in the post above the person stuck with it long enough to make it work but I think it can be done.

The first option would be to remove the key and rotate the flywheel 12 degrees CCW to advance the timing back to where it should be (or an offset key if possible). I would strongly recommend using a dial indicator to find TDC, degree marking the flywheel and using a timing light to verify the ignition is firing around 20 degrees BTDC at 3000 RPM. I went through all this with my TRX/CR hybrid lighted ignition system post and described it there.

If you aren't comfortable running the flywheel without a key and setting the timing manually, the next option would be to find an 01 or earlier flywhyeel which has the keyway cut in the correct position for the TRX crank and ESR plate. According to the karting site the 01 flywheel worked fine with the 02 stator.

Another option would be to have a custom adapter plate made that rotates the whole CR stator CW 12 degrees, advancing the timing back to where it should be.

Hope this helps!

[chronicsmoke]

Good info mx91a, thanks for that!

I've serached that topic a few times but could not find the answer like you wrote it here.

[Grande Huevos]

Originally posted by mx91a
The 2000-2001 ignitions are the most desirable to swap onto the TRX for their digital CDI over the 99 and earlier ignitions. Unfortunately Honda totally redesigned the CR250 engine in 2002 and decided to go with electronic servo controlled exhaust valves amongst other (major) changes. In doing so they needed to modify the ignition to control and power the powervalves, hence the CDI with more connectors, need for a wire harness and other extras that were not present on the 00-01 ignitions. I believe it can be adapted to the TRX engine, leaving off the extras that were needed for the powervalve. The main problem lies in the flywheel, with the 02 and up having the key way cut 12 degrees off of the 01 and earlier. This must have been due to either a change in the location of the keyway in the crank or change in the orientation of the stator mounting plate onto the engine. Here is where this difference was discovered:

http://www.ekartingnews.com/viewtopic.php?t=66607&postdays=0&postorder=asc&start=60

It LOOKS like the 02-up stator plates have the pulse generator in the same location relative to the stator mounting plate and holes as the 01 and earlier but it is tough to verify without having them side by side. This means that when you fit an 02 ignition to the TRX engine with an adapter plate designed for an 00-01 ignition the timing will be retarded by 12 degrees. Here is an older thread where someone tried to fit an 02 to his TRX and it exhibited all the problems of a severely retarded ignition timing (hard starding, extremely hot exhaust, no bottom end power):

http://www.exriders.com/vbb/showthread.php?s=&threadid=446502

The fix should not be too difficult and there are several options you can go with. I'm not sure if in the post above the person stuck with it long enough to make it work but I think it can be done.

The first option would be to remove the key and rotate the flywheel 12 degrees CCW to advance the timing back to where it should be (or an offset key if possible). I would strongly recommend using a dial indicator to find TDC, degree marking the flywheel and using a timing light to verify the ignition is firing around 20 degrees BTDC at 3000 RPM. I went through all this with my TRX/CR hybrid lighted ignition system post and described it there.

If you aren't comfortable running the flywheel without a key and setting the timing manually, the next option would be to find an 01 or earlier flywhyeel which has the keyway cut in the correct position for the TRX crank and ESR plate. According to the karting site the 01 flywheel worked fine with the 02 stator.

Another option would be to have a custom adapter plate made that rotates the whole CR stator CW 12 degrees, advancing the timing back to where it should be.

Hope this helps! YES thank you very much!!! i was kinda upset after reading that it wouldnt just bolt right up. But i think the easiest fix (at least for me) is to buy the 01 fly wheel if thats all i need. I dont think they cost to much either. After i tinker with it i will post my results for those interested.

[hartwill]

It's hard to tell from the picture but this cr250 ignition adaptor I have is adjustable, so your saying that I can use all the 2002 ignition components with this adaptor? Just rotate the pick up and adaptor 12 degrees to the left (counter clock wise)?
http://i1180.photobucket.com/albums/x407/hartwill/Snapbucket/4a8d4639-86f9-4c7d-b8d3-b0360c1f41dc.jpg

[mx91a]

It's hard to see the adapter but that ignition looks like a 90s CR analog. Can you remove everything to see what the adapter looks like and if it has the same two stator plate mounting holes as the later models?

[hartwill]

This is an old picture. I wander If they changed the mounting between the years. This ignition is currently on my quad but I have a new motor on the way I was hoping to use this 2002 ignition on. Here's the only other pic I have, probably not much good. Oh and somewhere along the line I figured out this ignition was from a 1992 or 1994 cr250 can't remember witch but it still seems to work quite a bit better than the trx.
http://i1180.photobucket.com/albums/x407/hartwill/Snapbucket/b93f05e2-b836-408c-9e23-242a949abb01.jpg

[mx91a]

I just measured 3.75" center to center of the mounting holes of a 2001 CR250 stator plate.