Ok, Im getting back to work on my bike, and I figured this might be one of the last bumps in the road.


My coil buzzes when I have they key on, and kill switch set to "RUN".

Ive done a quick checkthrough on the wiring and I cant find anything that would indicate why this would constantly loudly buzz while the keys on?

Has anyone had this problem? is my coil shot?

Does the bike start?

yeah the bike starts. it just runs a little sloppy and backfires a lot.

When I put the plug wire on the block, it constantly archs. probably 500 times per second

Im not an ignition pro, not in the least, but Id want to isolate the cil electrically & test with an ohm meter & see if the coil is goofed up or if its the signal the coil is getting. If the coil tests okay, then Id have to look at the ignition electronics,,

Testing with voltmeter should be easy, set to impedance touch the terminals and see what resistance you get, if you get infinity you have an open circuit, no good. Also touch each coil terminal one at a time to the battery negative, it should read zero, if you get any other number there's a short. I believe that would determine if the coil is doing its job but we have some electric wiz on this board.

As you can see, one coil lead goes to the run/kill switch and the other to the CDI (magic sh!t box).  The CDI opens (or vise versa, never can remember which, dam electrons) the coil to light a fire in the hole.

So for you to have a continuous spark there has to be a defective component somewhere.  Hopefully it's in the wire leading the CDI.  Cause otherwise it's the CDI, and that's a lot of bucks.

Look at the tops of the capacitors ( the blue tubes with the gray stripes & arrow, standing up), if one is domed, its done.Notice theyre scored lightly. Thats so when they Do overpressure, they pop before they pressure up like a mini pipe bomb.  I cant see anything that looks messed up,

Jut get a cheap ohm meter( Youre gonna need one, whether you want to use one or not)  & check the coil out. Post the readings. The coil cant just tell the plug to fire unless its being sent a signal to do that, but, checking the coil is so easy that I wouldnt think of starting anywhere else. .

You just turn the key on, dont even hit the start button & the coil starts firing the plug?


& a test lite,, gotta have one O those,,