79 GS550L does not start!

[79550]

I have very weak spark on 2 plugs (1 and 4) and no spark on the others (2 and 3). Is there any other option than both coils going bad? Seems odd that both would die out. The bike would once start, sputter and die (espcially if I hit the throttle). Now, nothing other than the sound of the starter.

Any ideas? Just don't want to run out an replace coils if it could be something else.

Thanks!

[Dave8338]

I have very weak spark on 2 plugs (1 and 4) and no spark on the others (2 and 3). Is there any other option than both coils going bad? Seems odd that both would die out. The bike would once start, sputter and die (espcially if I hit the throttle). Now, nothing other than the sound of the starter.

Any ideas? Just don't want to run out an replace coils if it could be something else.

Thanks!

First, before you hunt down the new coils, Check your charging system. There should be 12.4V from post to post on the battery, with the bike OFF... 14.5 - 15.5+- at 4,000 RPM's (you won't be able to check the running voltage until you get it running again. If the numbers vary much from these, the next step will be to locate all of your wire connections ALL OF THEM...and take them apart (bullet connectors and grounding points) and clean them. Copper pipe flux/cleaner works great for this. Then treat them to a dose of dielectric grease and put things back together. Also, pull the mounting bolts that hold the coils to the frame and give them the same treatment of flux/cleaner and grease. Then, re-run your your tests.

If your static voltage 12.4+ looks good and you still have no spark on the #2-3 coil, pull the plug cap off, cut about 3/8" off the wire and reinstall. Check for spark...if nothing, you'll most likely be looking for coils. If it is a charging issue ie. stator or r/r, do a search here and you'll have more info that you can digest! You'll want the charging thing figured out before burn out a new set of coils.

[Steve]

I agree with Dave on the voltage issue. You must have a well-charged battery for the bike to run decently. If you want to try something, connect your bike to your car with jumper cables WITH THE CAR ENGINE NOT RUNNING. Now try the bike to see if it sparks any better. If it runs better, check your battery and charging system. If it is not any better, your problem remains in the ignition system. But, before automatically condemning the coils, check the pick-up coils and ignitor and all the connections between them. There is not much to the ignition system, does not take long to check it all.


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[79550]

Thanks, I have a weekend project ahead of me.

I will report my findings...

[79550]

Well...

After gearing up to check the charging systems, I decided to check the spark again. Same issue as before, but this time I got an random spark out of the plug that previously had none. I decided to take a carb cleaner to the plug to clean it up. As much as I hate to take a hit to the ego, thats all my problem was. Dirty plugs. The 1 and 4 and 2 and 3 sequences were just coincidence.

Nice to be running again though. Gotta love the easy ones.

Thanks for the help.