82 GS550L Weak Spark/Single Spark

[cev318ti]

Hello all,

I have been fighting a no start on my 550 and have come to a dead end. I've chased down a few leads and tested but still no hard results pointing me in the right direction. So I ask all of you what can I do next?

I'll start by stating everything I have gone through so far:
-New plugs gapped to .032"
-New NGK boots installed
-Tested across wires: 25K ohms on both coils
-Tested primary: 4.23 ohms on both coils
-Checked voltage at coils while engine is turning: ~9 volts on both
-Checked voltage at coils while engine is not running: 12 volts on both
-Battery holds at ~11 volts (+/- 0.3 volts) while cranking
-Attempted to clean contacts of points, they were in pretty good shape but I am pretty unfamiliar as to how they operate
-Laid the connected spark plug on the cylinder head and strangely enough I will get one spark but then nothing. Tested all four leads.
-The bike has 8186.9 miles on the clock, garage kept for as long as I've had it.

I am at a loss as to what to check next. I would greatly appreciate any advice or knowledge.
I do have the pdf of the shop manual so references to pages within are welcome.

Thanks in advance,
-Shawn

 

[cowboyup3371]

If your battery is only at 11 while cranking what is it at rest? I think it's possibly too low and you should start with a known good battery

 

[tom203]

-"Attempted to clean contacts of points, they were in pretty good shape "

so this means someone converted this bike to points?? How long have you had this bike? Have you see it run?

Put your location in your signature - there might be a member nearby to lend a hands on .

 

[cev318ti]

I dunno about any conversions, I am unfamiliar with how points and condensers work but from what I do know it did not look like conventional points. Behind the pickup wheel (governor?) are two arms that are in contact with the shaft (crankshaft). Is there an article on BassCliff's website or on here that explains the ignition systems on these bikes? Some models come with CDI and an ignitor box, some with points. I will try to post a picture showing what I have I have rode it a good distance after getting it running this past fall but it started to act up. I've owned it since April '14.

I will be buying a new battery to cross that off as a possibility for a no start.
Thanks guys, I will continue the hunt.

*Edit
I looked at parts fiches for the 82 and there is an ignitor box on those models. I've seen something that resembles the ignitor box located under the airbox assembly. (http://www.bikebandit.com/oem-parts/1982-suzuki-gs550l/o/m139522#sch265527 part #1).
The 'points contacts' I cleaned were on part #5 in the same diagram. Is this a retrofit of CDI from a points system?

 

[mike_of_bbg]

An 82 should definitely have electronic ignition, not points. The igniter should be mounted to the underside of your airbox: there's really nothing to adjust on the inductive pickups or the igniter. You can check the impedance of the sig gen pickups, and they should be 60-80 ohms. Make sure all connections are clean. Running volts at the coils is pretty meaningless; standing is more important. That doesn't look like a big voltage drop - want to see <1V between volts at battery and at the coils. A healthy battery is a must (got a charger that puts out <2A?).

My gut says igniter (and that you need to check your charging system when you get it back to running), but that may just be colors of my own personal experience...

 

[tom203]

"Behind the pickup wheel (governor?) are two arms that are in contact with the shaft (crankshaft)"

The latter sounds like the advance mechanism, so you do have an ignitor system - they came from factory this way. Unfortunately, this model ignitor has less than stellar reputation. But first double check all connections in ignition system,cuz you might get lucky.
so it no starts now,.....What maintenance work have you done on this bike?
Do any spark plugs appear to fire during cranking?

edit.... You said " Attempted to clean contacts of points " what item did you clean?

 

[cev318ti]

Thanks for the replies guys!
I cleaned the mechanical advances but in hindsight I assume that was pretty pointless since they are nothing more than spring loaded counter weights. What problems does this ignitor system usually have?
The only maintenance I've performed so far is what I've mentioned above. The carbs were rebuilt (following the write up on BassCliff's site) and I can smell fuel coming from the combustion chamber when I remove the plugs. I've removed plugs and tested for spark coming from all four wires by laying it on the cylinder head and watching for spark. The most I can get is one spark during startup then nothing else for a couple minutes.
There are four wires connected to each signal pick up, one of which read 64ohms, no resistance at the other three. Are they all supposed to have resistance? What would indicate failed signal pickups?

 

[mike_of_bbg]

There are four wires connected to each signal pick up, one of which read 64ohms, no resistance at the other three. Are they all supposed to have resistance? What would indicate failed signal pickups?

Four wires to *each* pickup - or four total on the plate? On the stock ignition there should only be two wires per pickup - and one of those is common to both. If you follow the wires from the signal generator, they should lead to a harness with 3 blades. Those 3 connectors are one "return" from each pickup and the common. I cannot remember the colors or which one is common but you should be able to figure it out with a little examination. The resistance between the common and each of the other pins should be 60-80 ohms, so 64 ohms is just perfect. If you take both dedicated leads against each other you should get the sum of both (e.g., 64*2 or 130 ohms).

I can't recall if the rotor/sig gen is a Hall effect sensor or not (I think so, but I'm not really *that* deep in electronics). but basically when the raised parts of that rotor pass by those pick-ups, a small electrical "pulse" is generated and sent back to the igniter. The circuit in the igniter gets that pulse and that causes the igniter to break the ground to the associated coil. When the ground breaks, the magnetic field in the coil collapses and generates a high voltage across the secondary, firing those two plugs. What I believe happens (but never did get to test) is that the ground is actually switched to the other coil to build that magnetic field. Then in another half-turn of the crank the next coil fires and the ground is switched to the other. Etc., etc.

So, if you're only getting one spark, then the igniter is not switching the ground over. Could be that only one pickup is working. If the ground never switches back over you won't get a field built to collapse. Also could be a bad igniter. The sig gen is easy to test and is just a coil so should be pretty reliable. I'd trust getting a used one. If the igniter is bad, there are 3 basic remedies:

1) Get a new one. Yes they are still available, but at a very high price of $400-500.
2) Get a used one. Prices vary. Getting a 30-year-old used igniter is somewhat risky though. They don't always fail hard, so even if they're "tested" you could be getting one that will quit after it gets hot - like after 30 minutes of riding (ask me how I know).
3) Replace your ignition with a Dyna S DS3-2. $120-150, and it's new.

If your igniter is bad, there's a high likelihood it is bad because your Regulator/Rectifier is allowing too much voltage into the charging system and it damaged the transistors. First order of business after getting the bike running again is to check the charging system for this!

 

[cev318ti]

That's great stuff! Thanks so much! This gives me a road map to go by as I eliminate probable causes. I will be testing the signal generators tonight/tomorrow and post results. I'll also start budgeting for a Dyna ignitor. My original intent for this bike was to flip it (picked it up for $300 with a title...) but the more I put in it the more I want to keep going. I guess this is what ya'll feel for your machines . Thanks again!

 

[cev318ti]

Quick question: Does that Dyna Ignition setup take the ignitor box out of the ignition circuit?

 

[mike_of_bbg]

That's only for early points models. Electronic ignition GS550s 80-82 use the DS3-2. Technically if you look at your igniter it's Kokusan (i.e., KD), but DS3-2 is the right one.

Did you narrow down your issue?

When I installed mine - and I assume this is still true - they included a spacer for use with EI systems, but it was too thick. You can find a washer that's thinner with the same I.D., or machine down the spacer or the end of the rotor about half a millimeter. It doesn't need to be ultra precise, but you want the rotor to be able to turn/advance freely without enough gap that it could slip off the mechanical advance mechanism.

 

[cev318ti]

Does that Dyna Ignition setup take the ignitor box out of the ignition circuit? Or would it still use the stock ignitor box?

 

[mike_of_bbg]

The igniter is "built in" to the sig gen unit. It wires right to the coils and you can remove the igniter (I did).

 

[cev318ti]

Great, thanks! I went ahead and ordered the Dyna kit as well as coils and wires. I want to start fresh with the ignition system seeing as it's looking like I will be keeping this one.
Thanks again for everyone's help! I will update after parts come in and are installed.
-Shawn

 

[cev318ti]

Well the Dyna kit came in today so I will be installing it tonight. Will post results after the coils and wires come in. Also, is there a write up on setting the position of the pulse generators?

 

[mike_of_bbg]

There's a write-up on BassCliff's site about installing the Dyna (that was on a points bike though; nonetheless it wires right up to the coils except the power lead). I borrowed and used an inductive timing light for my install, but there's a static method documented as well.

http://members.dslextreme.com/users/cbsaunders/gs/upgrade_to_electronic_ignition.pdf

 

[cev318ti]

So is that how the ignitor is taken out of the loop? How does the dyna wiring differ from the ignitor circuit? My coils have a connector each, one has white(ground) and orange/white(common power) the other has black/yellow(ground) and orange/white(common power). I'm having trouble visualizing how the circuit should look after wiring in the dyna

 

[Nessism]

Coil relay mod will help increase voltage at the coils. Don't think you can expect a fat spark with only 9 volts.

 

[mike_of_bbg]

Coil relay mod will help increase voltage at the coils. Don't think you can expect a fat spark with only 9 volts.

He said the coil voltage was 12V. 9V was "turning", so there's got to be some sort of average of dwell/charge to that number.

 

[cev318ti]

Well, she starts! After a good while of spinning over it started up and went straight to 5k and bounces between 3k and 5k. I'm crossing my fingers its just all the fuel vapor that got dumped into the combustion chamber from spinning over so long but we will see tomorrow. Thank you guys so much and thank you mike_of_bgg! Anyone know of what can cause an incredibly high idle?