HI! that is the story:
i have 1994 xlh, dual fire. (2 wires from the egnition 1 from the killing switch on the coil)
i changed the top engine gaskets, after assemble the bike the engine cranked but there was not spark... i bought new coil to spark wires, still no spark (the plugs are good), i bring new coil, nothing.
i have 1994 xlh, dual fire. (2 wires from the egnition 1 from the killing switch on the coil)

my question: there can be something in the bike that kill coils?
thank you very much!

 

Check your ignition switch. Might not be sending voltage to your coil.

 

thank you! ignition do send signal... i mean can be a situation that some short circuit will completly kill a coil?

 

Not that I'm aware of. Sure you have your RUN/STOP switched to RUN? You have spark when turning engine over? Ignition wiring connected properly?

What do you mean by "dual fire?" You have two spark plugs per cylinder, or, both plugs spark simultaneously? I think most Sportsters fire both plugs no matter which cylinder is charged to fire. I think you can buy aftermarket coil/ignition systems that fire each cylinder individually.

John

 

Subscribed to study what drives the coil in a 94 Harley. ECM, electronic ignition or points. The answer is electronic ignition. My two cents. You should be able to check coil with a resistance meter. Will need a service manual or a good friend on here to give your the value. The trigger for it is under the timer cover and it is electronic. If it is bad, after you replace it, be sure to put a dc volt meter on the voltage regulator wire going to the battery and with it running at about 2000 rpm should be around 14.7 volts dc more or less. Now this is important. Flip the meter to AC. The reading should be zero. If it shows any AC, the diodes in the regulator is bad and this AC voltage will kill the ignition sensor under the timer cover that controls and fires the coil in short order.

 

thanks a lot guys for help!
i dont have a spark (tried 2 different coils). i afraid now to try third coil because i suspect that something in the system burn them up...
i have 2 wires from the egnition and 1 wire from killing switch. my first mistake was to connect the kill switch with negative to the coil... do you think that is could make big trouble in the system?

 

The Sporty is single fire on 2004 and later models.

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My 94 only had 2 wires, until I added the tach. Remove that third wire and re-test. It doesn't come from the run/stop ("kill switch") button. If it is from a tach, it goes on the positive.

 

Why do you think it's the coil and not the trigger? Switching wire probably would not hurt coil other then spark would be weakened since it would be jumping wrong direction on spark plug. However when the 12 volts is put on the large wire windings of the coil it completes its circuit thru the trigger, the trigger cuts it at correct time (engine timing) and the high amperage current creates the high voltage low amperage in the fine wire and that creates the spark. With out the on/off trigger the coil will not work but is not broken. The kill switch just cuts the on/off trigger out of the loop . Keyswitch cuts 12 volts off coil.

 

i think that its the coil because i tried 2 different coils that was good before i put them on my bike (i tested each separately)