Vintage '85 kx 125 issues

[Hillclimb#42]

Ok guys have a couple of easy ones. Here's some background to the 'ol smoker. My buddy picked up an old '85 125, in hopes of getting his son into something other than video games and trouble. He rebuilt top end on it and she fired up fairly easy considering the time it had been parked. She had a few leaks and smoked like there was not one crank seal doing its job. The clutches were froze together and the drum brakes were dragging, but we still took a couple laps around the yard. Let's just say ther was no mosquitos in the neighborhood for awhile. Anyways, it was obvious that the bottom end would need rebuilt too, or we would never be able to set the jetting. She was parked again until we could get the bottom end done. You know teens, the boy was ready to tear it up without it being right, and tried to ride in its condition. He coulnd't get it running though. Then his Dad tried to start it, nope. He didin't seem to get a spark. He brought it back over to see if we could look at it and tell him what he needed to buy or if he was overlooking something simple. Of course we thought "plug", or "no gas" , something that was monkeyed with possibly. We looked it over and also could find no spark. I eventually pulled the flywheel cover to find the timing way off. The owner said that he pulled it off for visual inspection after the problem of no fire. I tried going over connectors, cleaning ground connections and swapping plugs, but no spark. Now this is the funny part. I held the electrode on the cylinder head, on the frame, with my hand....no spark. I kept trying things and going back to looking for spark, but nothing. I thought I should try my 250 with the same test. I got NO SPARK!!!!! What the @#$%@? It runs well. I essentially tested the test and it failed. So how is the best way to test for spark? How would you tell if the problem is magneto or coil if there is no spark? Also, we will bet getting it running, but I am 1000% sure it will be for sale soon for anyone interested. 

[jazg]

i had the same spark test issues, shocked the hell out of me one time but yeh, still runs!

[Hillclimb#42]

Turns out that after using the search engine and reading some different topics that briefly discussed this, I found one thing that seemed reasonable. Evry bike's manual has the testing methods and they may vary from bike to bike. By process of elimination, with a logical order, everything tested right except CDI. I still felt like I was only guessing and I didn't want to buy extra electrical parts as there's never returns on electrical parts. The manual suggests taking your coil and CDI to the dealer and let them test it to cover your a**, but I'm not sure they provide that service. I have a hard time getting parts on anything from dealer as it is.
  This is what I learned as a summary. Flywheel is a big magnet and you would probably know what happened, if it lost magnetism. It would take a very hard hit to hurt it. Stators that have all wires connected are fairly bullet proof as well. Manual suggests cleaning contacts, if there's any question. Then its down to wiring, CDI and coil and their grounds. Visually inspect the wires for damaged insulator. Coil is pretty simple in design and can be tested easily. Power goes thru it to ground causing the coil to step up voltage to send out of the plug wire. Plug wire and boot can have issues on their own. Make sure all ground wires are all clean and tight. If all that checks out, then bammo you have to buy a 200 dollar ignition. Oh yeah, don't forget to eliminate killswitch issue. It unplugs from the ignition. It could get stuck and kill the spark.