Intermittent Spark Issues: 1982 GS1100e

[randaroo]

I have an intermittent spark off one coil only.(The other sparks just fine.)
Is it safe to assume that that coil needs replacing or am i on my way to something else?

[lucabond]

You can swap the coils to see if its bad. Take the wires from 1 and move them to the other. 1 coil fires the 1 and 4 plugs which is the coil on the left as you sit on the bike. The other coil on the right as you sit on the bike fire 2 AND 3. So swap the wires from 1 coil to the other both the plug wires and the 12 volt and ground wire and see if the coil that wasnt firing does now. If the coil then fires its wire supplying the 12 volts and or the ground wire or the pickup or the ignition box but you will know if the coil is bad or not. Good luck.

[randaroo]

i put my timing light onto the leads and that is what indicated the intermitent pulse(spark) from the two plug leads from the same coil.
There is spark but only every second or third cycle where the other coil leads are regular and constant.
Prior to the long lay-away, i only rode the bike for a few months. The bike would stumble on start up and would pop on dceleration. i;m sure it had a lot more power in the bag which makes me suspect it always had the faulty coil.
But if i switch coils and find the signal is still intermitent to the one side, then what? Or is that stupit?
(Coil is much cheeper than a signal generater)

[GSJONNY]

Hmmm

Ensure ur coil leads havn`t traveled away inside from the spark cap 1st. Then - have u done the mod taking the loom wire from the light loop and wired it straight to r/r? If so, whip out the plug from that cylinder, check it for being oily, double check the spark plug gap with attention to detail! You can`t assume the problem is your coils, its expencive to do this and horribly so if you find afterwards that it isn`t your coil..... Also whip off your sygnal end cover - have a gentle clean and ensure thers no debri or residue retarding the timing. If everything `was` working, then there is a reason for it not to be so now..... Do you have good plugs? Have you recently done any work? `Attention to detail` is my key point...... I hope this helps!

[randaroo]

i tore down the engne so there may be inconsistancies all over.
Best advice, carfuly check all the terminal connections and inspect wires. another Guiness for GSJONNY
Can a coil fail partialy like this or are they either alive or just dead, no inbetween?
Mmmm, does the signal generater serve one side for each coil? (Sorry for the stupit question)

Clearcoat today after a disaterious first try (Laquer thinner hidden in the gun somewhere, emerged at the last second.) Whaaaaaa, splat!
The gun is very clean now but i've misplaced the mid-filter... life is good.