850 Dropping cyclanders.

[nisom512]

trying to get my gs850 running right but the dang thing just wont it will totally kill once it happens. it seems like the bike is heating up and something is cutting out. something electronical. someone told me to feel the ignitor and see if it is hot or somthing? does this sound right? and it will be running just fine but then all the sudden I drop a cyclander and if I catch it quick enogh I can pull the throttle and it runs ruff and a lot of white smoke from the left exhaust. then I can keep it going but all the sudden it seems like another cylander cuts and then the whole thing just kills so I checked the plugs and cyclander #2 was super wet. and all the others were fine but for some reason #1 was Super black, along with #2 of coarse. What could be doing this?

When the bike first starts up/ when I let is sit for a bit it runs great then after about 1min at the most a cyclander drops and then about 10 sec later another does.

Is there something that runs the firing order that I could replace?

Please help
Thank you
Jake

[chef1366]

If you're sure the motor is sound and your carbs are clean it sounds ignition related.

[BassCliff]

Hi Mr. nisom512,

Coils? Plug caps? Are you sure the carbs are really clean and the air intake system is tight with no leaks? Coils and igniters have been known to become thermally intermittent. There are troubleshooting procedures in your manual. I'm too lazy to look it up right now.

Plug caps are cheap. You can also pull off the plug caps, trim about 1/4" or wire off, and reattach the plug caps to "fresh" non-corroded wire.

Double-check and re-clean all of your electric connections and grounds. #2 plug "super wet"? Hmmmm, petcock? Are the carbs really clean? You know the drill. Keep us informed.

Thank you for your indulgence,

BassCliff

[nisom512]

well what happens is one of the plugs stops stops firing almost like a coil shorts out. but if that were true the bike would still run on 3 cylinders. and I can keep it alive for a while but only if I catch it right away with the throttle. but then eventually it just kills. not slowly. does kill like it is starving for fuel, but a quick and painful death.

So my buddy and I swiched the coils to the other side and it did the same thing. oh and I know it is miss firing also because it runs fine(no miss) up till it heats up. then the RPM's dip so I can catch it by pulling the throttle(this is when the bike starts it's way to killing. and once I switched the coils nothing changed the same thing happened. so to me this means something else that is within the system is wrong.

So what tells the coils to fire?
what all is in the system for that electrical stuff. like for example the power from battery goes to We

[1978GS1000custom]

pull off the right side cover and check the points and condensers make sure nothings loose. check all the connections for a bare wire or a broken anything. check while its running what kind of readings you get from the condensers with a meter if you have one. check the coil ohms (i think 1-1/2 or 3 ohms rings a bell? but check the manual to be sure). check the wire that goes from that points cover area all the way up to the coils for anything wrong. this is gonna sound strange but it happened to me, check the connections in the fuse box for the ignition fuse and all the others. check the fuses themselves as well. #2 plug is wet most likely cause its not firing. check those plug caps and wire connections like bass cliff said too, moisture gets in there and gunks thing up and breaks the connections. your gonna need a volt meter or some kind of meter to check electrical devises. you can find a cheap one at walmart for 20.00 or so that will work just fine in the auto section. if it dosent have points and condensed and has electronic ign. it has a short or a field coil is getting weak. also, check the ignition (key) switch plug and connections make sure they are clean inside. unplug them and blow them out and replug them back in. let us know what ya find. cliff

[nisom512]

pull off the right side cover and check the points and condensers make sure nothings loose. check all the connections for a bare wire or a broken anything. check while its running what kind of readings you get from the condensers with a meter if you have one. check the coil ohms (i think 1-1/2 or 3 ohms rings a bell? but check the manual to be sure). check the wire that goes from that points cover area all the way up to the coils for anything wrong. this is gonna sound strange but it happened to me, check the connections in the fuse box for the ignition fuse and all the others. check the fuses themselves as well. #2 plug is wet most likely cause its not firing. check those plug caps and wire connections like bass cliff said too, moisture gets in there and gunks thing up and breaks the connections. your gonna need a volt meter or some kind of meter to check electrical devises. you can find a cheap one at walmart for 20.00 or so that will work just fine in the auto section. if it dosent have points and condensed and has electronic ign. it has a short or a field coil is getting weak. also, check the ignition (key) switch plug and connections make sure they are clean inside. unplug them and blow them out and replug them back in. let us know what ya find. cliff

WEll first of all it runs just fine there is nothing wrong about the way it starts and runs every time actually it starts right up no problem its just once it warms up that it kills. oh and 80+ model GS's dont have points.

So I kinda just figure that trying the whole bad connetion thing is out of question just cause it happens after about 2 min of running and the engine is warm so I would assume a bad connection would do something to the bikes running before that.

Thank you
Jake

[nisom512]

So what tells the coils to fire?
what all is in the system for that electrical stuff. like for example the power from battery goes to Where?

so I think i Understnad the system. so it starts at the ignition then to the igniter, then the coils then spark.....right? so if thats true would I need a new igniter or ignition possibly? I tested the coils by switching them and the same cyclander went out. so that eliminates the coils but now I need to know what one of the other things are broken.

Jake

[almarconi]

Hey Jake..is the bike still cutting off when it gets hot?

Here is the procedure to test the ignitor

Remove each spark plug of #3 and #4 cylinders, fit it
to the plug caps and place it 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 on ohms) with blue lead
wire on the ignitor side and - lead on the voltmeter with the green
lead wire.
The moment the test pins are connected the spark plug of #4 sparks
and the moment the tester pins are disconnected the spark plug of
#3 cylinder sparks.

[nisom512]

Hey Jake..is the bike still cutting off when it gets hot?

Here is the procedure to test the ignitor

Remove each spark plug of #3 and #4 cylinders, fit it
to the plug caps and place it 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 on ohms) with blue lead
wire on the ignitor side and - lead on the voltmeter with the green
lead wire.
The moment the test pins are connected the spark plug of #4 sparks
and the moment the tester pins are disconnected the spark plug of
#3 cylinder sparks.

and then repeat for #1 and #2?

and which one is the signal generator? and then will I know what one is the leade wire?

Thank you
Jake

[almarconi]

and then repeat for #1 and #2?

No need to repeat for 1 and 2, remember that when 4 fires, 1 fires and when 3 fires, 2 fires.

The signal generator is under the cover on the right side of the engine. Either look at your wiring diagram or look inside the cover and see what colors the wires are.

Look at your ignitor there should be a green wire and a blue wire.

[twr1776]

So I kinda just figure that trying the whole bad connetion thing is out of question just cause it happens after about 2 min of running and the engine is warm so I would assume a bad connection would do something to the bikes running before that.

I am not trying to be critical but have you actually checked all the ignition circuit connections and grounds? You could also check/clean the main ground to the frame. As others have suggested you should check & clean all of them to eliminate an intermittent problem. I am no electrical engineer but it sounds like heat is causing your ignition to cut out. Unless you verify all your connections and grounds are good your testing of the other items might not be accurate due to bad connections before the tested item and it could give you false test results. Checking wires and cleaning grounds is a lot cheaper than buying parts that you might not need. Eliminate one area of the problem at a time and move to the next. Connections & Grounds first IMHO.

[BassCliff]

Hi,

If I may, I'll copy and paste a nice troubleshooting article from Mr. Matchless. You can also find it on my website.

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

[nisom512]

I am not trying to be critical but have you actually checked all the ignition circuit connections and grounds? You could also check/clean the main ground to the frame. As others have suggested you should check & clean all of them to eliminate an intermittent problem. I am no electrical engineer but it sounds like heat is causing your ignition to cut out. Unless you verify all your connections and grounds are good your testing of the other items might not be accurate due to bad connections before the tested item and it could give you false test results. Checking wires and cleaning grounds is a lot cheaper than buying parts that you might not need. Eliminate one area of the problem at a time and move to the next. Connections & Grounds first IMHO.

Check and mate you are right it is worth it any ways !

Hi,

If I may, I'll copy and paste a nice troubleshooting article from Mr. Matchless. You can also find it on my website.

Thank you for your indulgence,

BassCliff

I read threw I will try some of thos things but the bike is cutting when it gets hot. it starts up and runs great untill it gets hot. I think next time I go home I am going to film the bike running and you guys can see me keep it running and what happens.

cause it is running good then all the sudden it trys to kill. and a bunch of white smoke starts pumping out the left lide. so i know its raw fuel but up till that point it runs awsome. and plug two is fouled when I pull it out right after this happens.

Jake

[BassCliff]

Thermally intermittent components are just about the hardest to troubleshoot. You almost have to "shotgun" them. That means just start replacing stuff and test, go through a bit of trial and error. Have you tried taking measurements when the machine is hot? Hot coil resistance versus cold coil resistance?

How long do you let the motor run while it's standing still? Do you have a fan blowing air across it? These air-cooled motors don't like to bake while they are stationary.


Thank you for your indulgence,

BassCliff

[nisom512]

Thermally intermittent components are just about the hardest to troubleshoot. You almost have to "shotgun" them. That means just start replacing stuff and test, go through a bit of trial and error. Have you tried taking measurements when the machine is hot? Hot coil resistance versus cold coil resistance?

How long do you let the motor run while it's standing still? Do you have a fan blowing air across it? These air-cooled motors don't like to bake while they are stationary.


Thank you for your indulgence,

BassCliff

shotgun method I like the sound of that!!!!. about 2-4 min then it kills. no but will put a fan on it. I will test for hot and cold resistance I am really thinking it is the ignitor do you have a clue on how much thos cost? for a new one.

Thank you
Jake