No Spark...

[Stephen072774]

I just started the new guy thread a couple days ago and I'm having a problem.  The last 2 days I haven't been able to start the bike.  Heres what I've done so far:

After I got home with the bike I removed the haedlight flaring.  I removed the headlight and then put it back not disturbing the wiring.
The temp is about 45-50F so that shouldn't be a factor.
The bike won't start.  Just keeps turning over.  It has a strong battery, it spins the motor fast.  I thought bad gas.  So I drained the tank by the hose that goes to the petcock, drained the carb bowls, and add new gas.  I set the petcock to PRI and still no start.  I did get a back-fire or two.  

So still no start.  Just turns over and over.  I pull out the plugs, they look dark, and wet/oily.  I cleaned them up and put them back in, still nothing.  I leave them out, (connected to the wires) and hit the starter and they are not sparking.  (it was night)

So that seems to be it, no spark.  Would it have back-fired if I'm not getting some spark?  I'm new to the bike and I thought maybe I hit a kill switch I didn't know about.  Keys on, headlights on, clutch in, in neutral, red kill switch on, kickstand down.  Is there something I'm doing wrong?  Do I need to check the stator? :dunno:

[GRU]

maybe your spark plug cables are bad....maybe the spark comes once in a while and that's how it backfired....you filed up the cylinder with gas while trying to start it and then the cable moved or something, and that spark plug got a spark...

try to see if you have any bad wires that are related to spark plugs

[Diderich]

When you pulled the spark plugs out and said they weren't sparking..were you holding the plugs near to the block...there needs to be a good ground for the spark.  When I'm not sure i put a screw driver up into the the spark plug wire and hold it so that some of the metal part is near to the engine block.  It should spark from the rod to the block.  This also helps to eliminate the spark plug as the cause.

Strange that both spark plug wires would go bad at exactly the same time, I assume it was running before, recently?  I suppose i should go back to your other post and look...oh bother.

Also, when any of the various kill switches are engaged the bike won't turn over at all, so that's not your problem.

The manual can also help you through some trouble shooting.

[Stephen072774]

When you pulled the spark plugs out and said they weren't sparking..were you holding the plugs near to the block...there needs to be a good ground for the spark.  When I'm not sure i put a screw driver up into the the spark plug wire and hold it so that some of the metal part is near to the engine block.  It should spark from the rod to the block.  This also helps to eliminate the spark plug as the cause.

No, I didn't have it close to the block.  I was just looking at the end of the spark plug and expected to see a spark jump across the spark plug gap.  Does the spark have to reach the block?  Shouldn't it be visable across the gap at night?

Yes the bike was recently running, and fairly new.

[The Buddha]

OK the spark plug's hook electrode needs to make contact with a metal ground of the bike... else it will not spark.... its a spark, not lightning... cant jump more than a couple of mm. People rest them against the cylinder block usually.
Cool.
Srinath.

[Stephen072774]

OK the spark plug's hook electrode needs to make contact with a metal ground of the bike... else it will not spark.... its a spark, not lightning... cant jump more than a couple of mm. People rest them against the cylinder block usually.
Cool.
Srinath.

OK, i didn't know it had to make contact with the block.  I'll try again.  

Thought I had found the problem for a minute. :x

[KevinC]

And another thing is, if you crank engines with electronic ignitions, without having a grounded sparkplug or somehwere for the high voltage to go to, you can damage the electronics. Hope the GS ones are tough!

[Kerry]

I can't really see both spark plugs (or both spark plug wires or both ignition coils) going bad all at once, at the same time. I wonder if a connector has wiggled loose?

My 1999 wiring harness is slightly different than your 2001 wiring harness, but I think they're close enough for this discussion.  (The connectors may be a different shape or color, but the wire counts and colors should guide us through OK.)

Take a photographic look at the connectors I'm talking about:


The white connector on the right has 3 wires that pass through it.  If that connector is loose no signal will get from your signal generator coils to your spark plugs.  Ditto for the 4-wire black connector in the picture that I replaced by the 4 pink connectors.  (Long story - can you say "battery corrosion"?)  You will be able to determine WHICH 4-wire connector is the right one by following the 3 wires from the first connector - in the direction AWAY from the wiring harness.

Check those two connectors.  If they seem to be "well connected" we can try something else.  (If it looks like we'll have to try to something else, start dusting off your ohmmeter....)

EDIT: Changed link from sisna.com to bbburma.net

[Kerry]

One other thing.  If it looks like you'll be doing a lot of tests for spark, you might want to rig up a purpose-built tester:



The nails are somewhat sharpened.  I selected their size so that a spark plug wire would fit snugly over the shaft of one of them after I cut the head off.  The red wire is auto "primary wire" (18 gauge?  16 gauge?) and the nail gap is around 9mm -- per the Haynes manual.

You can buy a ready-made device at the auto parts store that does the same thing, but with an adjustable gap.

To use it:

* Leave the spark plug in the engine
* Push the "boot" of the spark plug wire onto the headless nail
* Attach the clip to a good ground point (You can even use the metal end of the still-installed spark plug)
* Hit the starter button
* Look for a nice "fat" blue spark across the nail gap.[/list:u]

EDIT: Changed link from sisna.com to bbburma.net

[Stephen072774]

thanks Kerry I read a lot of your past posts to diagnose my problem...

I got it running tonight.  I obviously fouled the plugs.  Put in new plugs and a squirt of starter fluid in the intake and it started right up.  

I learned its easier than you think to foul the plugs.  I also learned to add more than a gallon of gas to clear the res.

Is it safe to shoot a little starter spray in the intake on cold mornings?

[yamahonkawazuki]

ive used wd-40 to get mine to start, another tester can be made by aking 2 spark-plugs, turning 1   180 deg, and taping it securely to the other, plugging (if wires are long enough) in wires spinning her over. ive used the wd-40 2 ways, 1 into the plug holes, (kinda risky), or into the airbox
 thats how i got my gs to start after sitting for a year, it actually ran good on year old gas too :dunno:

[The Buddha]

OK Its not easy to foul plugs.... IMHO, atleast not on the GS, and its not hard to start really, but you need to get it jetted right. But once you do that it is easy. BTW how was it fouled, gas or oil or what.
Cool.
Srinath.