Ignition problem on an 85 KDX 200. Help!!!


Sep 8, 2003
I just purhcased an 85 KDX 200 and it ran great. Spark got weaker and weaker under load until dead over a week or so. I have had the coil tested and it appears to be functional. Checked the resistance to the magneto and it is right on, except excactly opposite of what the book says, hopefully just a typo? So I pulled the mag cover off and a lot of water poured out, guessing the guy pressure washed to clean it up. Anyways the magneto still puts out 15-25 VAC when hand cranked with no spark plug, and the trigger coil seems to be functioning. Now the CDI still charges up to around 100 VDC and also seems to drop a few volts when triggered. When I hook the CDI to the ignition coil nothing makes it through the coil. So I am wondering if that is because the magneto is not sending enough juice to make it through the coil? Anyone know how much voltage should come out of the magneto? I have heard between 50-100 VAC. Thanks in advance.


Aug 20, 2002
I can not give you specs for the voltage etc., but in my experience, you will probably need a new (or rewound) coil to go inside the magneto. When you are convinced that the coil is the problem, there are a number of places that will rewind the magneto. Check out the small classified ads in Dirt Bike or Dirt Rider magazines.

Good Luck,
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