Only One Coil Sparking

[brian]

Hi,


I have a Suzuki GS650GT and having problems starting. Only one of the coils are sparking. When I switch the wires over from the working coil (BLACK/YELLOW & ORANGE/WHITE) to the none working coil (WHITE & ORANGE/WHITE) then that coil is working and the other one is not. So both coils are fine. I have gone through the whole wiring loom to check wiring and everything seems ok. I have done all the OHM tests on both coils and they seem to be ok.


My question is. Is it the the CDi (Ignitor) or the Signal Generator that is dead. if any....


You can view the GS650GT Wiring Diagram (in color) attached.


Please.. Any help on how to diagnose further will be appreciated. Anyone that has maybe gone through the same issue...
Thanks in advance

 

[tom203]

Disconnect the blue and green wire coming from signal generator....measure across them and look for ohms of about 300

 

[brian]

Hi, Thank you for the info. I checked the ohm. Im getting 350 ohm. So does that mean the Signal Generator is fine? That only leaves the Ignitor right? Or can it be anything else?

 

[Brendan W]

Could it be the coil supply plug is corroded?
What voltage are you getting at those plugs?

 

[tom203]

Double check the electrical plug from ignitor to coils..could be corroded. The ignitor on this model 32900-34210 ? is very durable, but doesn’t like a high charging system voltage

 

[abaton6]

, I am having the same issue. I'll follow this thread, hoping someone smarter than me will help find the culprit.. Also the plug wires have ben pulled, without marking which ones go where. Any help with that would e appreciated.
​

 

[abaton6]

Double check the electrical plug from ignitor to coils..could be corroded. The ignitor on this model 32900-34210 ? is very durable, but doesn?t like a high charging system voltage

Tom, I seem to have lost my shop manual. Where is the igniter?

 

[Grimly]

, I am having the same issue. I'll follow this thread, hoping someone smarter than me will help find the culprit.. Also the plug wires have ben pulled, without marking which ones go where. Any help with that would e appreciated.
​

Assuming the wiring is still standard and nobody's cross-connected the feeds to the coils, as you look at the coils from the rear, the left hand one fires cyls 1 and 4, the right one fires 2 and 3. Normally the HT leads for 1 and 4 will be longer anyway.

 

[brian]

Double check the electrical plug from ignitor to coils..could be corroded. The ignitor on this model 32900-34210 ? is very durable, but doesn?t like a high charging system voltage

Hi Tom, Thanks I double checked wiring. I have opened my complete wiring loom removed all hard plastic wrapping etc.. All wires are 100%. I also measured the OHMs of the signal generator (I'm getting 350 ohm). That seems to be fine. Only thing left I can think of is the ignitor. It looks so good though. No corrosion, rust, nothing. It looks brand new...

Anyone else have any idea how to test the CDI, if there is even a way?

Thanks for all your help guys

 

[tom203]

Tom, I seem to have lost my shop manual. Where is the igniter?

The ignitor is on a steel bracket mounted underneath the air filter box...the r/r is there too. Wires from it run up to two electrical plugs ..one a 4way and other 2 way.

 

[tom203]

Hi Tom, Thanks I double checked wiring.

Anyone else have any idea how to test the CDI, if there is even a way?

Thanks for all your help guys

Not easy to do but you can try this method in this link..step 11 etc
http://members.dslextreme.com/users/storagecliff/images/electrical_odd-n-ends.html#A17

best test is to install a known good unit and see if that corrects the issue...I?ve tested 5 of this ignitor and all worked fine, so a used unit would be a safe bet

 

[brian]

Hi,

I have gone through the complete wiring loom now from front to back. Can someone tell me if the igniter must be grounded to the frame. It seems like the guy that had the bike before moved stuff around. Should the actual igniter body be grounded to the frame?

 

[Gorminrider]

This is from the GS650 wiring diagram....
YES. Generally, the mounting bolts will do this,(see below text) but ANY Black/white stripe (B/W) needs to be "grounded". The ones shown coming off the top of the "igniter" attach to the loom's ground bus wire, that attaches to the frame at it's ends...

but note that this diagram from a 650G shows ANOTHER ground too..the one from the bottom with the "tree" connection. This usually denotes a bolt to casing ground - I won't say it always does. Some devices can be mounted to insulated places and they might provide a ground wire for this situation...

 

[brian]

Thanks, That makes sense.

 

[Gorminrider]

Heres a discrete diagram I made for a 650 Ignition system. It won't print very well due to ping background but the pink makes all the wires show up...the idea is it helps to focus on just the wiring that pertains to ignition.

 

[Gorminrider]

somewhere, maybe at Bass-cliffs site , downloaded a pdf named "Repair_and_Fault_finding_GS1000G_Ignitor.pdf" by member "Matchless" and in it you will find a test for an ignitor.
seeing as you are having trouble with one coil, here's part of it
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. You should not test any resistance between these two wires to ground. If this is in
order you have proved the pickups and the wires to be good.
14) 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.
15) Next test for 12 volt between the Orange/White wire and the Black/White wire going into
the igniter, this proves whether your igniter is getting power.
16) 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 then ground the plugs
and locate them 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.
17) 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.

But be sure to check the other stuff too-connections, coils e-youve alredy tested ohms at signal generators but ohms from a multimeter don't always indicate faults in COILS very well...



BikeCliff's Website

 

[abaton6]

Thank you for that link! Very informative. I checked the ground connections on the igniter, I found a thick cloth "washer" on the ground bolt. I can't think of a reason for it to be there. Can you?

 

[Gorminrider]

thick cloth washer? well, starining myself, but perhaps the igniter case didn't sit flat on the plate, but a steel washer would do too, so no. It's a mild entertainment trying to understand a PO's thinking.. ("previous owner")

Still, even the cloth washer needn't be "in the way" of a good ground if the bolt itself lands on shiny metal and is threaded into a tapped lug on the frame...

since one side is sparking, the case ground is unlikely to be the main issue.

 

[brian]

Wow, thank you , will go through this in detail this weekend...

 

[brian]

Thank you very much for this. Does it mean if I ONLY wire the above diagram, i should be able to test start. Even if nothing else is connected (like lights, gauges, etc..)