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Greetings KDX Riders- In need of some help. Here’s the story. Picked up a 1988 KDX200 for a winter project. Bought with no spark, seller indicated it was a bad cdi. I tried another OEM cdi from a known running bike, still had no spark. Ohm checks on ignition coil and source coil were slightly out of spec so those were replaced as well. Source coil I got from Ricky Stator and checks out good, ignition coil was sourced from eBay from a 1988 kx250, which I understood was interchangeable and ohm checked good. Finally had a spark, but was very weak and intermittent. After reading several posts about flywheel magnets falling off and being refastened incorrectly, I decided to check the order of the magnets and they were indeed re-epoxied in the wrong order NNSS. I corrected that issue so they are NSNS with north being across from keyway. I now have a great spark, however, when kicking over the bike I am getting a wicked kick back and no start. I realize this most likely some kind of a timing issue, I have checked and rechecked the stator plate position and it is perfectly lined up with the timing mark on the case. When I re-epoxied the magnets, I was very careful to get everything aligned properly with the alignment bumps in the flywheel. I am unsure what to do next, any help would be greatly appreciated. Thanks in advance.

The only things I can think of, and I'm no air cooled KDX expert, is that KX CDI has too mucg ignition advance for a KDX or the magnet pattern is incorrect... in other words, the S's are where the N's should be and vice versa.

First thing I would do is try retarding the stator plate to it's maximum position and see if that helps or even eliminates the problem.

SS109 wrote: 02:59 am Mar 30 2025 The only things I can think of, and I'm no air cooled KDX expert, is that KX CDI has too mucg ignition advance for a KDX or the magnet pattern is incorrect... in other words, the S's are where the N's should be and vice versa.

First thing I would do is try retarding the stator plate to it's maximum position and see if that helps or even eliminates the problem.

Thanks for the reply. So the cdi is from a kdx, it’s the ignition coil that was from a kx250. After sleeping on this, I believe I screwed up the magnet sequence, as you noted could be the problem. I originally thought N went adjacent to the keyway, but just saw an older post that stated otherwise, with S being adjacent to keyway. I have tried retarding the timing some and result was the same…kicking back so violently I’m afraid I’m going to break the woodruff key…something is way off. Planning to try resetting the magnets.

So, I also just noticed my flywheel has an “F” stamped on it and I don’t know what to make of that. I thought it would’ve had a “C” stamped on it since it’s an ‘88? If it’s been switched with another model flywheel, does anyone know what it may have come from? I don’t believe there are any “F” series KDX models. I will try and post a pic shortly.

Aftermarket coils cause a fair bit of timing advance inadvertently in the CDI itself from higher voltage, and the KX spec coil may be different in that regard. Timing being off will definitely cause kick back with too much advance. I'd say the magnet theory of North/South alignment being off is probably the correct theory though if no range of timing adjustment (dialing back the advance) fixes it. Can the source coil be installed backwards? That's a slight possibility also, I believe they can which will cause frustrating issues troubleshooting.

PowerDynamo / Vape.eu ignitions fit that bike and come with a new flywheel, FYI... Keyless design with fixed stator plate.
And 12v higher output lighting system.

Chuck78 wrote: 07:05 am Mar 31 2025 Aftermarket coils cause a fair bit of timing advance inadvertently in the CDI itself from higher voltage, and the KX spec coil may be different in that regard. Timing being off will definitely cause kick back with too much advance. I'd say the magnet theory of North/South alignment being off is probably the correct theory though if no range of timing adjustment (dialing back the advance) fixes it. Can the source coil be installed backwards? That's a slight possibility also, I believe they can which will cause frustrating issues troubleshooting.

PowerDynamo / Vape.eu ignitions fit that bike and come with a new flywheel, FYI... Keyless design with fixed stator plate.
And 12v higher output lighting system.

Thanks. I tried retarding the timing some and made no difference. I’ve also come to realize after reading other posts on here that having specific N or S magnet opposite the key shouldn’t matter, only that they alternate N-S-N-S, which is my current set up. I went back to the ignition coil that came on the bike just to rule out the KX coil being part of the issue, same result. I believe the source coil installation is correct, but I will double check.

Since I had never had this bike running, I hadn’t messed with the carb settings yet. After kicking it over a few times I’m smelling a lot of fuel, and even some leaking out of the exhaust port. The idle had been turned all the way in and air screw was completely closed. I did have the carb apart a while ago for cleaning, had a 55 pilot and 160 main, I believe stock jetting should be 48/155. I have to recheck the float height still. Saying all this, I believe it may be getting flooded…read excess fuel could also cause kick back. Might be sort of a wild card, but I plan to dig in to this a bit more. Does this sound like a reasonable hunch? I won’t be able to mess with for another couple weeks because of work.