weird spark problem

[r.t.snake]

I have an 82 550l and after sitting for a month won't start. Has fuel and intermttent spark. Fires occasionally but wont start.
Here's the weird part:
pulled out a plug and laid it on the head- cranked engine, no spark but then moved it away from ground and have spark. If I ground the side of the plug then no spark but if I pull it away slightly "Voila -a spark" It's not a nice fat blue spark more of a yellowy one????

Any guesses.

[computronic2040]

I suspect we might be in the same boat!

[thcash]

I had a similar problem on my '81 GS100G. After an extensive complete rebuild, it didn't run as well as it should have - it was missing during idle, picked up a bit at higher rpm's. While idling, #3 cylinder would miss - but would begin to fire if I pulled the plug boot nearly off the plug. Seems it had carbon tracks down the inside of the boot, which was sending the spark to ground rather than through the plug. I also could hold the boot in my hand while the engine ran, but received only an annoying shock, not the JOLT you would expect. Bought a set of Accell coils, and solved all my problems...runs better than new! After 25 years, I would replace the coils and wires..they have to be pretty worn out.

[r.t.snake]

Hey thanks for the tip. will check it out after super.

RT

[nert]

You probably just need new spark plugs. A fouled plug (not necessarily fouled to the eye) will allow the current to ride the "foul" to ground with out a spark.
Foul=shorted
Giving the plug and auxiliary gap (moving it away from the head) forces the spark to "build" and then jump the gap. Kinda like you having to jump over a stream once they removed the little bridge that was there.
Cleaning the plug may not help.

[r.t.snake]

Thanks for the suggestion. As a matter of fact I came to the same conclusion and will try new plugs tomorrow.

RT