running bike suddenly shut off - no spark?

[residentgearhead]

my dad has an 82 gs650 that he hasnt ridden in a few years. i pulled it out and bought a new battery for it to get it from freezing up forever. after a little bit of turning over it started up and ran pretty well.
the last time i was running it i was pulling it back into its parking space (idle or little throttle) and it suddenly shut off.
i tried to fire it back up and it just turns and turns, doesnt even stumble.
all lights and starter work well.
i checked the left side spark plug and there was no spark.

ideas?
i dont know a whole lot about motorcycle electrical systems, but from what i've learned through searching it could be a coil. if it were one coil then the other 2 cylinders should stumble, and i doubt both would fail at once, right?

[chef1366]

First I would check the connection between the spark plug boot and the wire.
Were the carb bowls drained before storing? If not you can't imagine the horrors that lie within.

[Big T]

I'd check the kill switch

[chef1366]

I'd check the kill switch

You're right. That could be it too.

[wdavie]

If its spinning but not firing I'm guessing it won't be the kill switch, if that's not working surely the bike wouldn't turn over?

[residentgearhead]

thats what i figured as well about the kill switch. are there two wires coming from the kill switch and one could have broken (for the ignition) but one is still working (for the starter)?
and no, i dont think the carbs were drained, but it was running at pretty close to 100%, suddenly shut off and now doesnt have spark, so its probably not a carb issue.
i'll check other spark plugs when i get home to see if they have spark.

[old_chopper]

Use a volt meter and see if you have 12 volts going to the kill switch, if so is there 12 volts leaving the switch. If yes the check to see if you are getting 12 volts to the coil(s). It is most likely a broken wire or unplugged connection somewhere. It's almost always something simple like that.

[residentgearhead]

Thanks, I'll check that when I get home.
So battery>switch>coil>spark plug is the power path to the coil?

[fenderfreek]

Yep, pretty much.

[BassCliff]

Greetings and Salutations!!

Hi Mr. residentgearhead,

There is a list of things that must be checked/cleaned/repaired/replaced when you resurrect one of these classic GS motorcycles. There really are no short cuts to get your machine back to a reliable state. That list is in your "mega-welcome". It's how I say "Hi!".....

Here is your very own magical, mystical, mythical, mind-expanding "mega-welcome". Please take notice of the "Top 10 Common Issues", the Carb Rebuild Series, and the Stator Papers. Now let me roll out the welcome mat for you...

Please click here for your mega-welcome, chock full of tips, suggestions, links to vendors, and other information. Then feel free to visit my little BikeCliff website where I've been collecting the wisdom of this generous community. Don't forget, we like pictures! Not you, your bike!

Thanks for joining us. Keep us informed.

Thank you for your indulgence,

BassCliff