Troubleshooting new to me 1986 GS 550 ES (G)

[Steak]

Recently purchased low mileage '86 GS550ES (17173) which was running strong and smooth yesterday. Parked and upon return the bike would turn over, but would not start.

It is getting fuel but no spark.

What are the obvious problems?

My suspicion is a faulty side stand switch as the dash light remains on whether side stand is up or down. Will the side stand switch interrupt the ignition? Is there a simple bypass if this is indeed the problem?

Any wisdom you can share would be welcome as I am not familiar with this bike at all.

Regards,

Steve

[elrico]

More info.eventually will be needed. How many times have you started bike and took ride of how many miles so far in ownership,were these rides done without stops/restarts or you stayed in saddle for full duration of ride.Time wise also,what was minutes/hours.Any noticable/suspect problems during rides.Did you have to use a battery charger yet.Does bike crank strong/fast or slow.Only starting brief history/ symptom dialogue,get ball rolling..Others will hopefully find your post soon.Like i say,more good exchange of info will develop better process.Be on watch for Mr.Basscliff's Welcome.

[Steak]

More info.eventually will be needed. How many times have you started bike and took ride of how many miles so far in ownership,were these rides done without stops/restarts or you stayed in saddle for full duration of ride.Time wise also,what was minutes/hours.Any noticable/suspect problems during rides.Did you have to use a battery charger yet.Does bike crank strong/fast or slow.Only starting brief history/ symptom dialogue,get ball rolling..Others will hopefully find your post soon.Like i say,more good exchange of info will develop better process.Be on watch for Mr.Basscliff's Welcome.

Current mileage: 17190

Total of three starts including test ride/inspection, initial ride upon delivery (less than one mile), final ride yesterday. I did have a couple of low idle stalls on the 16 mile ride, but the bike would restart robustly. On probably the sixth or seventh start attempt after parking on an errand ~16 miles got strong crank just as all prior starts, but no ignition. The bike probably sat for 10-15 minutes before restart was attempted.

It would not start in neutral nor in gear with clutch engaged. I had noticed for the first time that the side stand idiot light on dash was illuminated and would not go out whether the side stand switch was compressed or not, either by hand or by raising the stand. Ride time was about 20-25 urban city streets, bike ran strongly and gave no indication of trouble.

Miles ridden since purchase: 17 this was my first ride since test ride.

At roadside I pulled, inspected and cleaned all fuses in the panel. I pulled the number four plug and checked for spark - no spark. I pulled the side stand switch and jumped the leads - still no change on dash light, although there was a barely perceptible dimming. Vacuum line to petcock was functional as was fuel delivery to the carbs.

Roadside tinkering ultimately drained the battery to a point of weakened starter motor, so it has been on a trickle charger since this morning.

Thanks in advance for considering this problem.

[Steak]

More information to consider. Tried starting the bike again this evening and it did start after a bit of coaxing. But it seemed more like an inadequate fueling issue. The side stand lamp went out after the engine started up.

After the bike got warm and after roughly 0.7 miles of smooth and strong performance I pulled back into the driveway and shut it down. Tried starting it again and it was back to turning over without firing up. Again, seems more of a fueling issue at this point when the bike gets hot/warm. After the bike cools down once again it will probably start right up.

-SD

[BassCliff]

Greetings and Salutations!!

Hi Mr. Steak,

Make sure the petcock is operating properly. Make sure the vacuum and fuel lines to the petcock are in good condition, are not kinked, and are connected properly. Have a look at THIS ARTICLE to get an idea of what it should look like. I know yours has the funky "siamese" carbs, but you'll get the idea. If you need a manual, the '83 GS550 manual on my website will be close enough for most purposes. Feel free to download.

If the history of the bike is unknown, then you may have to go through all of the required maintenance. This means a full carb dis-assembly and dip, valve adjustments, air intake repair, etc. It's all in the maintenance lists in your "mega-welcome" below.

Now let me dump a TON of information on you and share some GS lovin'.

I just stopped by to welcome you to the forum in my own, special way.

If there's anything you'd like to know about the Suzuki GS model bikes, and most others actually, you've come to the right place. There's a lot of knowledge and experience here in the community. Come on in and let me say "HOoooowwwDY!"....

Here is your very own magical, mystical, mythical, mind-expanding "mega-welcome". Please take notice of the "Top 10 Common Issues", "Top 15 Tips For GS Happiness", the Carb Cleanup Series, and the Stator Papers. All of these tasks must be addressed in order to have a safe, reliable machine. This is what NOT to do: Top 10 Newbie Mistakes. 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. I will put you on my prayer list.

Thank you for your indulgence,

BassCliff

[tom203]

You may have a weak battery( and a poor charging system) that despite its ability to crank starter motor, the voltage drop might be too much for ignition system to fire consistently during some starting attempts.Right after a good trickle charge, the battery is probably at about 13 volts, but drops off rapidly especially if it's weak. Time to break out the multimeter and see what you got.

[koolaid_kid]

I agree with BassCliff and Tom. The first thing I would do is check the voltage at the coils: with ignition on, starter off, then ignition on, starter on. Your coils have two spade connectors on them. One connector is supplied 12V battery voltage. It should be orange w/white stripe. Rig something up where your multimeter is connected to this. Turn the key on. You should show battery voltage (~12V). Now press the starter button and watch the mulitmeter. If it drops more than 1-2V you probably have a battery issue.
Second, you really need to follow BassCliff's Top 10 list. It is thorough and well written.
You own a fine bike, but it is 25 years old and needs everything (charging system, ignition system, wiring harness, fuel and intake systems) brought up to snuff so you can enjoy your bike as it was meant to be enjoyed.
Best of luck.

[Steak]

Thanks to all, that makes a lot of sense. I'll get right on it!

[elrico]

Steak,Great recall/history on situation,so good ,usefull.juicy.Your experience sounds familiar.In the somewhat short time I last posted Re:.. WOW... All responders,.. ...

[kokar]

The reasons for not having Sparks is one of the following
a) switch 14 (ignition switch) can not work
b) switch 12 (engine kill switch) can not work
c) blown fuse or fuse box problem (rust contacts)
d) signal generator problem
e) Ignitor problem
f) battery problem