bryced1 wrote: Hey all,
Recently got a 83 KZ550 and cyl #4 wont fire. I pulled the plug and there is no spark. However, since I pulled #3 and got spark, I think I may have blown a coil. (read on here the sparkplug must be in the motor to act as a ground, is that true?)
Would like to test the coils to verify before buying new ones/ begin troubleshooting the ignition system. I dont have a shop manual and was hoping someone could point me to the appropriate procedures and give me a bit of guidance.
It is possible to damage a coil or igniter if you pull off one spark plug wire and don't let it have a connection to ground. More specifically, if you don't let one spark plug wire have a path to the other spark plug wire of the same coil, that coil may get damaged or the circuit in the igniter for that one coil may get damaged. It doesn't need to go to ground, but the plug wires need a path to each other. People use the engine as a way to complete the path because it is a conductor. A small air gap is ok, as that is how you check the spark. Don't go more than about 3/8" on the air gap, maybe 1/2".
If you have a spark on #1, then you should have spark on #4. They are a pair, which means they are connected to the same coil. Same goes for #2 and #3.
Make sure your plugs are paired that way. Sometimes people mistakenly pair 1 with 2 and 3 with 4.
