while I do believe 2002 and later setups can be made to work, the following article says they are different.
I know the flywheels on the 125 and 250 are keyed differently along with having the pickup coils mounted in different spots
I have ran the cr125 cdi on my cr250 stator and flywheel but I have not tried the cr125 stator and flywheel because the pickup is in a different location and creates mounting issues.
So I do not know if it is timed the same as the cr250 and 500
Basically if the key way on the 2002 cr250 crank is at the 12 O'Clock position while at TDC like the cr500 then it should work fine.
write up from here:
http://www.ekartingnews.com/viewtopic.p ... c&start=75
Hi Guys
I will add some explanitory photographs tomorrow as my camera batteries are dead!!
After Sid's post and various e-mails, I think that it is best if I clarify completely the situation with regard to fitting a '99 to '01 generator (8-pin plug) to an '02 onwards motor.
It appears that some people may have taken one of my statements that this was a straight swap a little too literally. The generator (rotor and stator) is a straight swop but there are timing differences which although mentioned in other posts may not have been 100% complete or clear.
Simply put:
When swapping/fitting a '99 - '01 generator to an '02 onwards motor and with the standard lower index plate in place, the ignition trigger point will be advanced by 12 degrees.
To correct this you can either:
1. Run the rotor without the key and replace the rotor 12 degrees clockwise relying on the taper to hold the rotor.
2. Remove the lower index plate and elongate both top and bottom adjustment slots to allow anti-clockwise rotation of the stator by 12 degrees. (this is entirely possible, but requires also removing the little hump near the top slot to allow sufficient elongation)
3. Programme the programmable CDI box to take account of the different offset (retard the whole curve by 12 degrees)
4. A combination of the above.
We tend to run the key in place, remove the lower index plate and run the stator fully anti-clockwise in it's standard slots. In this position the flange of the top mounting bolt will be sitting hard against the side of the little "hump" that helps retain the cable clamp. This gives 8 of the required 12 degrees and then we make the small programming change (4 degree retard on the whole curve) to finalise the correct setting.
Incidentally as a bonus moving the stator on it's slots decreases and cable stretch from the stator to the case grommet.
When fitting any new ignition and/or generator we always verify the firing position by testing either on the rig or on the engine using a strobe light. It is entirely possible that this will vary up to a couple of degrees from installation to installation.
If you are using an engine builder, ensure that he has verified the ignition curve either in your fixed or programmable CDI box relative to crankshaft position.
Anyone purchasing a complete system or CDI box from Viper Racing UK, will receive a fully checked unit and detailed fitting instructions.
We personally do not recommend the use of the standard Honda CDI box for kart use. But I know that Roger Miller, for one, has had some success with an '03 box
I hope that this clears up any ambiguity.
As always if you have any sort of question or doubt, please don't hesitate to ask and be as specific as possible.
Specifically Sid
The SPI '99 CR250 box will work with the '99-'01 CR250 generator when fitted to an '02 onwards motor using the methods above. Same applies to the standard Honda box, but this would not be my recommendation. In these cases I would say just elongate the slots to allow a 12 degree anti-clockwise rotation of the stator from the standard indexed position. Simple
Best Regards
Ian
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Ian Harrison