cdi help

[hartwill]

on my 86 250r i have a cdi and wiring harness that i am positive is from another bike. it only has one plug on it and all the others ive seen had two. however it does say ha2 does any one know what this is off of. oh and my bike still runs great with it. here are a couple pics.

[hartwill]

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[86 Quad R]

i believe that is from an '85 ATC 250R

The CDI shown in the photos is from a ATC250R 1985...not 86.

carlos.

[hartwill]

thanks. it seems to run good with this cdi. any pros or cons between 85 atc and a regular trx cdi??

[86 Quad R]

its been said that its best to run the cdi with its corresponding year flywheel and stator as each year trx or atc has its own set timing curve. there maybe a lil something to this as when i originally purchased my 86 trx it had a new crate 85 atc engine in it but had a 88 cdi. when that cdi went out on me i borrowed a 85 atc cdi from my buddies bike and i could notice a bit more "seat of the pants" in performance. hope this helps.

btw: since you have the 85 cdi on your quad you can determine if you have the atc fly wheel by removing the stator cover and inspecting the fly wheel. it will have a significantly smaller/lighter center hub.

[deathman53]

85 atc cdi and harness is different. The plug is different. 85-88 stators are the same and 89 is only different because of different plugs. The flywheels on almost every year are slightly different. 85 being the lightest. Honda played with the weight and +2/-2 spark advancement. Cdi's between the years were different to work with the flywheel. If you use an adjustable timing counter balance holder, everything is thrown out the window.