I recently tested my stator using a multi meter. For my '93 kdx200 I had to disconnect three wires and test for ohms resistance.
On mine the resistance stator should of been 304-456 ohms from the white/red to black wire. The lighting was 1.76-2.64 ohms. If you have a book that gives the resistance or somebody else on here does you should be able to tell if it good or not.
Yes I was checking the resistance, not voltage. My problem turned out to be a sheared woodruff key that keeps the rotor from flopping around. One of my other problems was not knowing how to use the multi meter. Got that staightened out.
Your stator should show resistance within a range(need to look in a kawasaki book to get the numbers). If it is open or too high then something is wrong. Sorry I am not at home right now to tell you exactly which is which. Maybe somebody here has a book and can give you numbers for your year of bike.
By the way I changed the stator and only later discovered that I was using the multi meter wrong. I got the new one from Ricky Stator. Live and learn.
Ok. Remove the seat and tank if you haven't already. Unplug the three wire connector coming up from the magneto. Should be somewhere around the tank area. Now check the res from black wire to blue, should be about 104 ohms. Then black to white/red, should be 142 ohms. Now blue to white/red, should be 38. If I remember right the last two in my book were switched, just a typo. I think I straightened it out for you though. If you want, black to yellow should be 0.54, but that is just for the headlight so it should have no effect. Also, all those figures have an acceptable range of + or - 20%. As far as voltage coming out it varies with RPM, but I had somewhere between 15-20 VOlts AC with a good hard kick with no spark plug. While your at it check you coil, primary to flange should be 0.22 ohms, and secondary (plug wire) to flange should be 7.2K ohms. Alot of shops will test coils for 5 bucks or so. Good luck.
I got my readings but they are low. I dont know if this means they are bad. My black to blue was 69.5.
My Black to white red was 107 ,
and my blue to white red was 38.3.
And I couldnt get any readings from my coil, but with a kick I could only see about 5v or so.
The '89-94 kdx service manual suggests that and I quote "if there is much less resistance than shown in the table, the stator is shorted, or the leads between the stator and the connector is grounded. Check the stator and the leads, and fix or replace the damaged parts".
Now theres some good advice from Kawi.
Stator failure is common on the older KDX's. Mine failed on my '84, a friends failed, and I've read about many others on this board. You can have it rewound (or rewind it yourself) for much less than the cost of replacement.
When mine went bad, the bike started getting harder to start, even with a fresh plug, good gas, etc... Eventually, it was nearly impossible to start. When anyone says their old KDX is having electrical trouble, I immediately think it's stator troubles. IMO, the OEM sator just doesn't last forever.