No spark ignitor gets hot

[Craig54]

Hi
81 gs 1000 g
She sat for about a month during the wet weather here in Auz. I put a new battery in and no spark..... Ignitor gets hot quickly with the key on and so does the left coil. I have been running all the test suggested but cant seem to figure it out.
any ideas?????
Craig

[pete]

Sounds to me like the ignitor may have failed and be grounding the left coil continuously.

I'd measure voltage at the coil, disconnect the ignitor and measure again.

I'm guessing with the ignitor disconnected your coil won't get hot, and manually grounding the negative side of the coil primary will fire a spark.

[mike_of_bbg]

Certainly the heat of the coil is not particularly interesting except as a reminder to not leave your ignition on for too long! Unless the engine is turning it's going to be grounding one of the coils continuously. Betcha if you turn the motor by hand 180 degrees after turning it on that it will change coils (or if not, turn it another 180 degrees). Don't do this for too long though; your coils have to dissipate about 50W of heat when they're constantly connected. You'll burn 'em out if you leave them on constantly too long. Take those plugs out before you try that - don't turn it by hand with the ignition on and the spark plugs in

The coil should fire when the ground is disconnected, not when it is connected. It's the collapse of the primary field that causes spark in the secondary. The grounding builds the field in the primary.

The stock EI system on the mechanical advance GSes is really pretty simple. What's probably going on in the ignition system is that, when the rotor triggers the signal for coil A, the ground is pulled from coil A and given to coil B. Then when the rotor triggers the coil B sig, it switches the ground back to coil A. Build-collapse-build-collapse. If the engine does not turn the ignitor never gets the signals to switch coils.

Have you gotten resistance readings for your coil primaries and secondaries? How about the sig gen pickups? Check your plug boots? What's your voltage at the coils?