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2002 yz250 wiring harness made to fit a 2005 motor

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Considering building a 2002 yz250 that is currently in a box. We currently have a 2005 yz250 motor that would take minimal effort to rebuild that could slide right into the current 02 frame. That being said, although the motors are almost identical between the two, I have found that the wiring harnesses are different slightly. I was just curious if anyone else has tried tackling this problem, and know whether or not the wires from the 02 could be rearranged and rerouted to fit the 2005 motor. Would I just be better off to try to pick up a used 05 wiring harness off of eBay and plug it into my current 02 cdi box?

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What difference did you notice.

I know the coil leads are different and there may be a neutral switch on the 05. You could easily change the coil leads but nothing would be as bulletproof as stock. The neutral switch is unnecessary.

 

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This is the easiest way for me to explain the differences.

The 2002 has fewer plugs

5906a2636ef78_2002wiringharness.PNG.0a2b30dc561d6969744894bd0fb65264.PNG

The 2005 harness is the one with the three plugs in a straight row.

5906a2646c1a5_2005wiringharness.PNG.f549b30c3f60bf7b48aa2b834a4dc11e.PNG

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Right, looks like the 05 has one extra plug which I would guess is the neutral switch. Does your 05 engine have a neutral sensor below the shifter?

It also looks like they changed the way the kill switch is connected so you would have to deal with that as well.

So the 3 in a row should be stator, kill switch, neutral sensor.

The 02 has the kill switch connectors near the coil.

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I will have to check later and see about the neutral switch on the motor. Do you think that it would work to buy something like this setup, that way you get the 05 wiring without changing the original? Would my current 2002 cdi be compatible with that harness you think?IMG_2060.thumb.PNG.5fc03dbd86e78245f12a77dd817de465.PNG

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Most of the wiring has nothing to do with the engine. Other than the neutral switch.

If you are using the 2002 kill switch and coil, you would want the 2002 harness. The stator in the engine is no different from 02 to 05.

The 2002 CDI will work with either harness with the exception of the neutral timing change. (Absolutely unnecessary)

Be very careful anything you buy isn't for a 4 stroke 250.

I could be wrong about any of the 2005 stuff but I know the 2002 wiring. It's a piece of cake 10 min. job.

 

I only know what I learned from putting a 2002 wiring loom on my 2000 so I could use a 2016 YZ250X CDI.

 

Edited by mikeylikesit
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Alright awesome I will probably go that route because I need to buy a coil anyway. I'm by no means at all an electrician and I wouldn't want to tackle something out of my range. Thanks for all your help. 

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The 05 motor will go right into the 02 frame and harness.  I've got an 06 motor in my otherwise completely 02 YZ

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