1986 GS550L spark problems

[Tarsyn]

Hello I am new to the boards. I just bought a 1986 GS550L. I bought it to give me something to work on in my spare time. It turns over fine (when it is connected to my battery charger) but I am only getting spark in two of the four plug wires. I switched wires from the coils and the other two wires then have spark as well. So I know it is not the coils or plug wires (I ohmed them out and they check out okay primary 3+ ohms and the secondary 33+ ohms). I traced the problem back to the igniter box or signal generator. The signal generator seems to check out okay at the plug but I am not so sure about how to check out the igniter box. I hope it isn't the problem. I did notice that in the signal generator the gap between the pickup is a lot larger on one side than the other. Could this be the problem? If it is my manual doesn't make mention of how to set the distance. Any help would be appreciated. If it ends up being the Igniter where would be a good place to find one. Thanks Travis

[Dave8338]

It sounds like either wires or plugs, if you switched wires and the spark follows the wire switch...I'de say wires or caps.

Welcome to the fourm, this place will surprise and may even frighten you.

Yo Basscliff...yu dare man?

[BassCliff]

Greetings and Salutations!!

Hi Mr. Tarsyn,

(Here I am!)

Here is your "mega-welcome". Pay particular attention to the "Top 10 Common Issues", the Carb Rebuild Series, and the Stator Papers. You'll find a couple of articles HERE that may help you troubleshoot your igniter and ignition. 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.

Thank you for your indulgence,

BassCliff

[Tarsyn]

Thanks for the welcome. I visited the sights as suggested and I am excited to know that there is so much information available. I do not believe the coils or plug wires and plugs are bad because of the troubleshooting I have done so far. I believe the problem is either in the Signal generator or the CDI Igniter. Is there any way to check the igniter without having a new one to compare it with? Thanks Travis

[Smart_Ace8]

I am also new to the forums with the same problem. I have a 1980 GS550L with good ignition coils and plugs, but no spark to 1 and 4. As we speak my problem is being diagnosed by a buddy of mine who is a bike mechanic. I will let you know what he tells me so we can get closer to solving this dilemma.

[chef1366]

Does the crank trigger wobble when turning? Look closely at the wires on the signal generator and make sure there are no breaks.
Do you have a mechanical advance?
Do you have manual? There is a way to check the igniter.

[BassCliff]

Hi,

Is there any way to check the igniter without having a new one to compare it with?

From the link given above:
--------------------------
Ignitor/signal generator/coil test
Originally posted by Mr. Billy Ricks

This is for an '85 700 but you can probably use the same tests for your bike.

Here's how to check the ignitor. Remove spark plugs 1 & 2 and ground them to the motor so they will fire when they get power. With the ignitor facing you, the plug on the right side of the ignitor is where the signal generator plug fits. The two terminals on the right side of that portion of the ignitor will be pin 1 at the front and pin 2 at the back. The two left pins will be pin 3 in front and pin 4 at the back. Turn the ignition switch on. With a multitester set a the X1 ohm range put the + probe on pin 2 and the - probe on pin 1. Plug number 1 should fire. Next put the + probe on pin 4 and the - probe on pin 3. Plug number 2 should fire. If this happens the ignitor is good and the signal generators are suspect.

As for testing the pickups, signal generators, measure the resistance between the two wires on each pickup. You should get somewhere around 130-200 ohms. If the resistance is infinity or less than spec they are shot.

To test the coils put one probe of the multitester on each of the terminals on the primary side of the coil. You should get 3-5 ohms. Check the secondary windings by placing one probe into each of the plug wires coming from one coil. Those would be 2 & 3 from one coil and 1 & 4 for the other. You should get 30-50,000 ohms for stock coils and 15-20,000 for aftermarket.

Here is another procedure to test the ignitor by Mr. almarconi

Remove the spark plugs of #3 and #4 cylinders, fit them into the plug caps, and place them on the cylinder head.

Remove the frame cover on the right side and disconnect the lead wire from the signal generator.

Connect (+) lead of voltmeter [set to ohms] with blue lead wire on the ignitor side, connect the (-) lead on the voltmeter with the green lead wire.

The moment the test leads are connected, the electrode of spark plug of #4 fires. The moment the test leads are disconnected, the electrode of spark plug of #3 fires.

***AND***

Testing The Ignition System
by Mr. Matchless

Properly localizing a problem with the ignition is sometimes a bit confusing and the following below should of assistance:

* Basic test, remove spark plugs. Fit them to the plug HT leads and ground them to the engine. Turn engine with starter and see if plugs spark. If any one spark plug does not spark swap it out. If the spark seems good on all 4 plugs, the ignition system is very likely in order. If spark is not present or very weak proceed with the following tests.
* Remove the tank, left side cover, seat and signal generating unit (pickup) cover at bottom right of engine.
* A good habit is to check the coils and igniter to see if they do not get very hot once the ignition is switched on, as this will most likely be the indication of a failed component of faulty connection or wire.
* If the spark is weak but present, inspect the HT leads and plug caps. Suspect coil wires and spark plug caps, or voltage at the coils and thus the battery condition. It could also be due to coils with partially shorted windings, but do not jump on this cause immediately, and they may get hot.
* Overheating coils with no spark may also be due to them getting a permanent full ground either from a faulty igniter or a grounded and pinched wire. Disconnect the coil plug connectors and proceed with tests.
* Measure the battery voltage directly across the battery terminals. If lower than approximately 12.6V first charge battery fully before proceeding.
* Next measure voltage over the coil connector plug, orange/white wire and the battery negative terminal. If lower than 12 Volt inspect the wiring for poor contacts and localise cause of voltage drop.
* Again measure directly across the battery, but pull off the spark plug leads to prevent engine from firing and swing with starter. While starter is turning the voltage should stay at least above 11 Volt. Also swing the starter with the headlights on to see that the voltage does not drop significantly at the coils while the starter plus headlights load the battery, which could prove that even if your battery is fully charged, it cannot give full or sufficient current and is on its way out or your starter may be drawing excess current (usually unlikely if starter is spinning at full speed) and pulling the battery down. If it drops much lower, charge battery fully or have it load tested and replaced if faulty.
* If all is well up to here you can assume your battery and the positive feed to your coils are in good order.
* With the coil plug connectors disconnected, use an ohm meter and measure the resistance of both windings on each of the coils. Exact resistance measurements are not too important, but continuity of the windings close to the approximate resistance values given indicates that the coils are in good condition. It must be noted that it is possible for the coils to only show up a fault when at higher operating temperatures, but this does not happen frequently.
Ignition coil resistance:
Between the two HT plug caps of the same coil, secondary HT winding, approximately 30 – 35 K ohm
Between the orange/white and white on the first coil and orange/white and black/yellow on the second coil, primary winding, approximately 2-5 ohm. If this test is within limits you likely have two good coils.
* Locate the igniter and disconnect the plug with the blue and green wires coming from the signal generator (pickup) at the right bottom of the engine. Test the resistance across these wires coming from the signal generator pickup coils, it should be approximately 250 – 360 ohm. If this is in order you have proved the pickups and the wires to be good.
* The little back box or igniter is now tested as follows. With the ignition on, kill switch on, test for 12 Volt DC between the orange/white and the black/white wires in the plug going into the igniter. This proves that it is getting the correct voltage.
* The next step is to prove whether the igniter is powering your coils. Remove all 4 spark plugs and connect the HT lead caps to a spark plug #1, #2, #3 and #4 which is grounded and located to enable you to see the spark. Ensure all the connector plugs are back in, except the one with the green and blue wires from the signal generator.
* To simulate the small voltage generated by the pickup coil, prepare an ordinary 1.5V dry cell with two wires red for positive and black for negative. Connect the negative black wire from the dry cell to the blue wire on the connector plug going into the igniter. Switch on the ignition and kill switch to power the igniter and briefly touch the red wire from the dry cell positive to the green wire connector going into the igniter. You should see a spark on plugs #1 and #4 when you touch the wire and on #2 and #3 when you remove the wire. If this works your igniter is in a working condition.
* One other check that is often overlooked. Run the bike at night with all lights off in a dark area and check that no sparks are jumping from the HT leads to the frame or tank. If so they may need replacing.
* At this stage if all tests have passed you MUST get a spark at all the plugs when everything is reconnected and the engine is turned with the starter.
* If a spark that was previously missing has mysteriously appeared, have a very good look at your wiring and connectors, as something may be making intermittent contact and corrected itself temporary when you moved the wires.
* If there is a spark, but the engine will not fire, it could be due to ignition timing, valve timing or fuel problems. Ignition timing and valve timing problems are more likely on a bike that has not run yet after being disassembled and more unlikely to be the cause if the bike was not taken apart and was running before.
* A quick test with a few drops of fuel directly into the cylinders before replacing the spark plugs and then trying to start will prove it to either the fuel system or ignition system.
1. If the engine then starts and runs for a few RPM's the ignition is correct and you need to look at the fuel and carburettor side.
2. If the engine does not fire, but occasional gives one load pop through the carburettors or even exhaust, it may be igniting when the valves are open, the valve timing may be a problem, cam chain or swapped wires from pickup – plugs firing at wrong time.
3. Other reasons could be extremely low compression, too tight valve clearances, thus not closing fully (usually unlikely on all cylinders at the same time, but plausible), carburettor faulty or dirty, fuel line, filter or petcock faulty. Filter can cause an airlock if not positioned properly to allow free gravity feed.
4. Then finally the ignition timing must be set properly. At less than 1500 RPM connect a timing light to #2 or # 3 spark plug and check that the timing marks line up for 2-3 on F, then move to #1 or #4 spark plug and check that marks line up for 1-4 on F. Check the advance by pushing revs up to 2350 RPM and the timing marks should both line up on the 45 mark behind the signal generator mounting plate through the sight hole at the top. The three mounting screws can be loosened and the mounting plate can be moved slightly in the elongated holes to meet this.
----------------------------

Thank you for your indulgence,

BassCliff

[Tarsyn]

I look forward to hearing what your buddy comes up with. I do have a manual I downloaded online with an add on for the 1983-86 gs550L. The manual is the suzuki manual covering all 550's. I found a schematic in the general section and I assume it applies to my 550L as well in regards to the igniter. It shows the pins for the plug in on the igniter numbered 1-8 and then a chart giving various ohm reading when pinning out 1-2 or 3-4, etc. I don't know if it is the right one however because on the pin out 1-1 through 1-8 none of the values are even close (they are supposed to be off and I am getting value readings) so either it is the wrong diagram or my CDI is shot or I am ohming it out incorrectly. A friend that works at a bike shop told me he didn't think that it was possible for the CDI to produce spark for only one set of coils. If it was bad it wouldn't work at all. So I don't know what to think. Any input/help would be appreciated. Thanks Travis

[Tarsyn]

BassCliff- Thanks for the writeup. I had posted just after you and did not get a chance to see that you had. I will run down your list of suggestions, looks like the answer to my problem lies in your recommendations. I will let you know if I get it figured out. Thanks Travis

[BassCliff]

BassCliff- Thanks for the writeup. I had posted just after you and did not get a chance to see that you had. I will run down your list of suggestions, looks like the answer to my problem lies in your recommendations. I will let you know if I get it figured out. Thanks Travis

Hi Mr. Tarsyn,

I won't take credit for those procedures. Those are from other forum members. I'm not that smart.

I try to collect the "best of" the GSR Forum on my website. Mostly because I know I will need this information one day so I put it where I can find it easily. Feel free to peruse my website and help yourself.

Thank you for your indulgence,

BassCliff

[chef1366]

Hi Mr. Tarsyn,

I won't take credit for those procedures. Those are from other forum members. I'm not that smart.

I try to collect the "best of" the GSR Forum on my website. Mostly because I know I will need this information one day so I put it where I can find it easily. Feel free to peruse my website and help yourself.

Thank you for your indulgence,

BassCliff

You are the GSR super geek!!!!
Gathering info like a pack rack.
It isn't for nil though!