I did something dumb, and now the the spark is very weak

[Guest]

My 1980 GS1000 was running fine yesterday. Then, like an idiot, I disconnected all of the electrical components connected to the battery box because I was thinking about moving everything around. I changed my mind and reconnected everything, but I'm afraid I may have reversed something. When I went to fire it up, all the lights turned on when I turned the key as usual, and then when I pressed the starter button, there was click and everything went dark. I disconnected a couple of things and then hooked them back up. Now all the lights work again and it turns over, but it doesn't want to start (I did get it started for a minute yesterday, but not since then). The only diagnostics I know how to do is check to see if there is spark. There is, but it is very faint (and not really across the gap...it looks like it is sparking down inside the plug).

What should I check next? Electrical work baffles me, so if you have a suggestion, pretend you are speaking to a 5 year old. Thanks so much for reading.

[cowboyup3371]

First off, have you checked all of your fuses - not just visually but with a test light or multimeter? Don't rely on sight especially if you have the older glass tubes since they can break under the caps.

If you don't have a multimeter then you'll want to pick one up before going much further. In addition, if you can put your location in your profile someone might be close enough to assist you.

[jvogan]

Thanks for replying. I did check them with a multimeter, and they are all still ok. I added my location to my profile.

[OldVet66]

Do you have the body of the spark plug firmly grounded to the motor when you are checking for spark? looping some bare tie wire under a screw and wrapping the wire around the threads to hold it should ground it and hold it in a easy to see position.

[azr]

I'm guessing you don't have the connections on properly that you took off, or they are pretty grungy and now that you've moved them they don't make a good contact. Take them off one by one and clean them up with some sand paper then make sure they're on good.

[jvogan]

I tried what you suggested with the wire. Seems like the same results. Spark is weak and not across the gap. Thanks for the suggestion, thugh.

[bonanzadave]

"I did something dumb"

Not really. You should do that on occasion to keep the electrical connections clean, tight and corrosion free.

I disconnected all of the electrical components connected to the battery box

Battery box or fuse box ? Post a picture....or ask for a picture of a batt or fuse box and make sure everything is as it was when the bike was running. Im guessing this is something pretty simple. Look on BikeCliff for fuse box tutorials.

http://members.dslextreme.com/users/bikecliff/

[jvogan]

Everything I disconnected was screwed to the battery box. When I re-attached the fuse box the first time, I didn't have both screws in, so maybe I didn't have everything grounded correctly and that's why it "clicked" and all power was gone?

I've cleaned up the connections on everything that I messed with. And then I noticed that a couple of fuses were getting very warm when the key was turned on, and it seemed like conductivity was not great across them. I removed all the fuses and cleaned the contacts.

I'm pretty sure everything is back where it was and the connections are better now that they were originally, but still no luck on getting a better spark or starting the bike. It still seems like I might have damaged something when I tried to start it the very first time.

[OldVet66]

That just confirms that you do indeed have a weak spark. I don't know much about the Suzuki electronic ignition and hope you didn't damage that but cleaning up the connections and making sure all your grounds were reconnected properly and cleaned if you removed any (black wire with a white stripe big ring connector). Follow all of those and see if you possibly burned one up. That would be an easy to fix. At least at that point if there is no change you know to dig deeper. You should be able to find your factory manual and tons of good stuff here: http://members.dslextreme.com/users/bikecliff/

[OldVet66]

Fuses can get hot because the fuse box may need a good cleaning or replacement or plugs, switches, and bullet connectors and grounds in the circuit may have a bad contact and is building up a resistance that is heating up the circuit. At any rate a full harness cleanup is in order, using Deoxit to clean and the Deoxit equivalent or dielectric grease on all connections and switches. Switch dissembly is better done in a real clear plastic bag so any small parts or springs that escape are not lost. Check out posplayr's signature line for electrical and charging health. If it is electrical, HE IS DA MAN!

[jvogan]

i'm not sure i understand, why does the existence of hot fuses definitely confirm the spark is weak?

[OldVet66]

That is not what I said. Using a good ground on the spark plug, you confirmed a weak spark. I said hot fuses were because of high contact resistances, simply an indication of a circuit going toward overload because of a lack of maintainence at the electrical contact points. Two separate issues, the harness maintainence is required and can cause, or maintained cure, a lot of electrical gremlins. I suspect you might have damaged your ignighter but before goung down that road clean up anything else that is well known to cause electrical problems on these old bikes. It's just possible it might fix your problem too. Check your battery and charge it. A low battery voltage will also make electronic ignitions fail to start the bike, I suppose weak spark.

[tkent02]

Have you checked the voltage to the coils?

[jvogan]

ok, thanks, i misunderstood. i just went through everything i could get at and cleaned it up. i also replaced the spark plugs for the heck of it. without expecting much, i hit the start button and it fired up and is running better than it has since i bought it. i don't know if it was the plugs or the connections (i should have tried one first before the other), but i'm just happy it's running again.

thanks to everybody who responded. it was very helpful... i'm learning more everyday.

[OldVet66]

You just learned the power of maintenance. I sent you a link that should have a factory manual with electrical diagrams, you should have enough information at hand now to learn a lot with a little help from your GSR friends. I just keep the manual in it's downloaded form and print the sections I need to work with.