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I'm having some weird ignition symptoms. I recently installed a dyna 3 electronic ignition, that I had working after some fiddling. Then the next day no spark at all when trying to start. After trouble shooting with dynatek, they suggested for me to send the plate assembly back to them for testing the circuit board. I decided to install the points to run in the interim. Well I found that the points didn't fire either. After some more tests, I got spark again. hmmm. I then decided to try the dyna3 again. I reinstalled the dyna, reset the timing and it ran fine. I put tank back on and got ready for a test ride, and then no spark again. I then noticed when I try to turn bike over while getting no spark, when I turn off the nail key, I got a backfire/spark. Does this mean there is something shorting or loose in the ignition plate, which is new. Any suggestions?

That's a tough one. It could be any one of a number of things.

Given that it affects points and the dyna, does help to narrow things down a bit.

Does the dyna still rely on a coil? Power to the coil would be my first check.

Power to the coil will be shut off via kill switch or ignition.

Some problems can turn out to be caused by the darndest, unrelated thing.

Sounds like the electrical contacts on your ignition switch. The only other thing in circuit should be your "kill switch". I know your switch plate is NEW, but I have seen other new parts not working also.

Thanks for the replies. I double checked the 12v supply to the coils and am getting 12.3v with ignition on. When turning the starter, with ignition still on, voltage drops down to between 10.2- 9.8 at the coil Then when I turn ignition off I get 11v at the coil, and a backfire/ spark. Maybe my original coils may be going out?
Edit: after reading Duane A's trouble shooting tips, I ordered some new dyna coils. I'll see if that helps.

Since you seem to get spark when the when you release the start button, it appears that the starter is drawing a lot of current, the voltage spike you saw with the backfire shows the coils may be OK, they fired at 11.0 volts. Sometimes the electronic ignitions are a bit more sensitive to minimum voltage levels when the bike is cranking. The fact that points exhibited the same problem is possibly an indication that the battery is at fault.
Had a similar problem on another make bike, with individual coils for each plug, they needed a minimum voltage at cranking to fire when cold. Had to buy a better battery with more cranking amps.
If your battery is relatively new check your grounds for corrosion. I would unhook the cables from the battery and check with a multimeter in the ohms position to see how much resistance they had.

Just to clarify, it sparks/ backfires when I turn the key off, not when I depress the starter button. The battery is less than a full year old, so I don't think that is the problem, since sometimes it was working fine. When it isn't sparking, it is dead, as opposed to a weak spark.

Coils.

Do you have oil and alternator lights when it won't start?

I agree, it sounds like the coils.

duantro wrote: when I turn off the nail key, I got a backfire/spark.

I can make my bike cough back into the airbox sometimes if I turn the ignition on and then off, without pressing the starter.

I've not heard of coils switching on and off.

Big question, was the bike running properly prior to fitting the Dyna?