lost spark for some reason

[achim1313]

Hey guys ...79 1100xs special.

I've been working on it and near completion. anyways it was going fine...let it sit over night and the following day when I went to go start it nothing.

checked out the plugs and not getting any spark on all 4.

all the wires are good and the connections clean. battery is fully charged.

surely the coils didn't go bad on me over night could they?

[LoHo]

It is your pick-up coils under the left side timing cover. There are a ton of posts about the "pick-up coil fix." You will find the wires are powdered inside their insulation and one (or more) has simply decayed so much that it no longer sends a signal.

[motoman]

79....hmmm......ballist resistor under tank maybe sounds suspicious.

[BA80]

Could be either or, but most likely it's a bad connection somewhere.

Silly question but is the emergency cut off switch in the run or stop position.

The most likely culprit is a bad connection on the ignition fuse particularly if you still have the original glass tube fuse panel.

[achim1313]

I bypassed the resistor just to check and still nothing. then I'm down to just a basic wire setup. yes it's done right, good solid connections all the way through. was running like a champ then sat over night and the next day no spark.

[BA80]

Have you got key on power to the resistor?

[Radioguylogs]

A thought

You probably know, but just in case....don't forget you need an electrical path through the plug you are testing and the complimentary plug that is fired by the same coil (1-4, 2-3).

I sometimes use jumper cables to connect the 'ground' of one dangling plug to the 'ground' of the complimentary plug.