WORKS TO TEST (W--K) (W--K) THE 1984 ATC200ES BIG RED , 1984 TRX200 AND 1984 ATC125M
 
 
BELOW IS FROM A CUSTOMER
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1984 200ES CDI Replacement, MythBusted.. (customer_post) - 3wheelerworld1984 200ES CDI Replacement, MythBusted..

After posting my dissection and repair of an 84 CDI i decided it was time to take this one step further, first off, the replacement of the CDI on a 84 since everyone is convinced its a hoodoo voodoo box that can't be replaced.

First off, yes the 84 is different then other years, but its nothing special. Because the 84 had reverse there is a reverse switch input which is a gray wire that is grounded when the sub trans is shifted into reverse, for some reason they decided for safety sake that you shouldn't be able to crank the starter when its in reverse, even if the shifter is in neutral.. I don't know why but this is how mine worked, if i had it in reverse to back into the shed and kicked her to neutral but left it in reverse before shutting off i couldn't then start it until i also moved the sub-trans lever out of reverse.

Anyway, i fixed my CDI as i posted in the other thread. And it was still running fine after days of riding, no issues loosing spark again, but the spark still didn't look that strong to me. I bought a new DR8ES-L plug and it looked a little better but still not what i would call an optimal spark and the plug seemed to be fouling again, i also noticed it would randomly pop while cruising along in 3rd-5th gear and half throttle or more, it was missing! So i decided since i have been through everything else electrical and mechanical on this BR i would replace the CDI.

First thing i did was go here

And purchase a CDI unit from him along with the male/female connector kit. Total cost of about $26 plus shipping. Local dealer wants $199.00 for a replacement CDI for the 84 and its special order. The CDI from DrATV has no reverse safety and it has no rev limiter function, so its a basic CDI but it works fine. It even fits the stock mounting rubber that the original was in, the size is roughly the same.

Follow the wiring diagram he has on that page with the CDI. I removed the contacts from the stock round connector with the intent to just put them in the shell of the new connector but a couple of the contacts looked pretty rough, someone had tried tightening them up before by pinching with a pliers. So i cut off the old crimps and used the new ones with the connector kit. I crimped them on carefully with a needle nose pliers then soldered each on as well to insure they stay put. Popped the wires into the positions following the picture on his site and hit the start button...

ROAR... Holy crap i about shat myself. I have never heard it crack over that healthy and it barely turned over with the starter, i would say first plug fire had it running smooth. No more pop while cruising and the idle is much better, though i have a throttle cable problem to sort out yet as i have to take apart the throttle and grease it so it returns fully back to idle without getting stuck just above idle.

As for the spark improvement?? From yellowish with the original CDI to a VERY strong light blue white spark, i put my spark tester inline before the plug and it has enough voltage now to not only jump the test gap in the tester but also the spark plug at the same time and still run while the tester is inline, before it wouldn't run with the tester inline though i did see spark in the tester.

So moral of the story, if you have an 84 get a new CDI for it if your having ignition or running problems!