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No spark!

47K views 55 replies 21 participants last post by  Emil 
#1 ·
I have a rebel and I cant get it to start. The starter will turn fine so I tested to see if my plugs were sparking and they are doing nothing but they look like brand new plugs. My bike sat for almost a year without a battery so I guess im asking is it possible for the plugs to just die like that??
 
#29 ·
The Black/white wire should have no continuity to ground if you want the ignition module to make a spark. It should show as an open circuit to the green ground wire. Switching the ignition switch to OFF should ground the black/ white wire and disable the ignition module.
 
#30 · (Edited)
Since I have a 1999 Rebel like yours, and I knew that there were a few switch settings that would allow the starter to engage, but not allow the bike to run, i.e. NO SPARK, and since I am not sure if you have completely ruled out switch problems as the culprit, i decided to document all the switch settings and accompanying operation on my Rebel.

If the kill switch is in the run position and operating correctly, there are no other switch positions that both allow the starter to operate and prevent the bike from running. There are several combinations that will prevent the starter from operating as well as prevent the bike from running, but if the kill switch is on and the starter turns, the bike should crank and run.

However if the kill switch is OFF, the bike will not run, i.e. NO SPARK, regardless of other switch positions. However there are a few combinations that will allow the starter to operate, even though the bike won't run.

If the bike is in NEUTRAL, the starter will operate regardless of whether the clutch is IN or OUT, or the kickstand is UP or DOWN, but the bike will not start with the kill switch OFF.

Also, if the bike is in gear 1-5, and both the clutch is IN, and the kickstand is UP, the starter will also turn, but the bike will not crank when the kill switch is OFF. The starter will not turn if either the clutch is OUT, or the kickstand is DOWN, when the bike is in gear.

Therefore, unless you have 2 switches that have both gone bad at the same time, the only switch that can malfunction by itself and cause your problem is the kill switch, if you have all the other switches set correctly.

Try cranking the bike with it in NEUTRAL, and the clutch IN, and the kickstand UP. The starter should operate regardless of the setting of the kill switch, but only have SPARK with the kill switch set to RUN.

If that doesn't get you SPARK, then in order to completely eliminate the OFF function from all switches, and therefore rule out any switches as the culprit, just temporarily disconnect the black/white wire from the ignition control module (CDI). This takes away the possibility of grounding the ignition, and it should have SPARK and RUN regardless of the switch settings if the starter will crank the engine.

If it will now SPARK, the problem is in the switches. If not, then the problem is in the ignition system itself, and the switches have nothing to do with it, and can be ruled out.

A note of warning though if you do this, all of the safety switches will be disengaged, and neither the ignition or kill switch will shut the bike down. You will have to choke it down to stop the engine. This is just for testing, and you should reconnect the wiring after you find and repair the problem.
 
#31 ·
Since I have a 1999 Rebel like yours, and I knew that there were a few switch settings that would allow the starter to engage, but not allow the bike to run, i.e. NO SPARK, and since I am not sure if you have completely ruled out switch problems as the culprit, i decided to document all the switch settings and accompanying operation on my Rebel.
---Thanks for you time! I can't describe my current level of frustration.

If the kill switch is in the run position and operating correctly, there are no other switch positions that both allow the starter to operate and prevent the bike from running. There are several combinations that will prevent the starter from operating as well as prevent the bike from running, but if the kill switch is on and the starter turns, the bike should crank and run.
---Yes, kill switch in RUN position, the starter works every time and no spark. (Also took it apart to examine and it grounds when off and properly moves away copper contact when in RUN)

However if the kill switch is OFF, the bike will not run, i.e. NO SPARK, regardless of other switch positions. However there are a few combinations that will allow the starter to operate, even though the bike won't run.
---No spark.

If the bike is in NEUTRAL, the starter will operate regardless of whether the clutch is IN or OUT, or the kickstand is UP or DOWN, but the bike will not start with the kill switch OFF.
---The bike is in neutral. Removed and verified that the kickstand switch works replaced and retract kickstand when testing bike for spark. Removed and verified that the clutch switch works(with multimeter) pull in clutch lever when testing for spark.

Also, if the bike is in gear 1-5, and both the clutch is IN, and the kickstand is UP, the starter will also turn, but the bike will not crank when the kill switch is OFF. The starter will not turn if either the clutch is OUT, or the kickstand is DOWN, when the bike is in gear.
---In Neutral, green light is on and I can easily push bike, verified. Kickstand UP. Clutch IN. Starter works but no spark.

Therefore, unless you have 2 switches that have both gone bad at the same time, the only switch that can malfunction by itself and cause your problem is the kill switch, if you have all the other switches set correctly.
---And the KILL switch to allow the bike to work needs to break contact and it does when pushed down to RUN.

Try cranking the bike with it in NEUTRAL, and the clutch IN, and the kickstand UP. The starter should operate regardless of the setting of the kill switch, but only have SPARK with the kill switch set to RUN.

If that doesn't get you SPARK, then in order to completely eliminate the OFF function from all switches, and therefore rule out any switches as the culprit, just temporarily disconnect the black/white wire from the ignition control module (CDI). This takes away the possibility of grounding the ignition, and it should have SPARK and RUN regardless of the switch settings if the starter will crank the engine.
---No SPARK. What!? I didn't try this. Who didn't tell me to try this before I removed and tested and replaced all the stupid switches!?!? I am about to permanently remove that wire to disable any additional future faults. I will try this tonight with the old and new CDI modules I have at home.

If it will now SPARK, the problem is in the switches. If not, then the problem is in the ignition system itself, and the switches have nothing to do with it, and can be ruled out.

A note of warning though if you do this, all of the safety switches will be disengaged, and neither the ignition or kill switch will shut the bike down. You will have to choke it down to stop the engine. This is just for testing, and you should reconnect the wiring after you find and repair the problem.
---I know I know... joking about leaving it off... geesh.

I wished I would have tried this before removing the stator/exciter cover and broke the gasket. I can just mount it back on for testing though.

Stator picture for fun. Cause it was real fun breaking the gasket to get this off.
 

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#36 ·
Did you verify the pulses from the exciter coil using an AC scale on your meter? The elephant in the room is the Ignition module itself.
Its possible for even a brand new one to be DOA.
 
#37 ·
---I have not verified that, I will reassemble the exciter cover and such and test that. I have not seen the value it should read yet, I will keep searching. Yes, it could be DOA. Is there a way to test the CDI without another motorcycle? I have not found the readouts for that either.
 
#38 · (Edited)
Sorry man, didn't know you had already gone that far. I have been meaning to check this so that I can make a sticky thread, but just now got the bike out again.

Regarding the gasket, mine is broken from the first time I took it off, but since it doesn't seal anything, I just made sure it was smooth and not overlapping and reused it. Been working fine ever since.

If yours is too torn up, the remove it all and cut a piece of thick paper like card stock, or thin cardboard. I have used the old panty hose packing boards for years, but they are harder to come by today.

To my knowledge, no one has ever come up with a way to test the CDI.
 
#40 ·

Old Work
:Back to no spark and what I have done.
-Tested kickstand switch, 0 resistance and 1 resistance in different positions
-Tested clutch switch, 0 resistance and 1 resistance in different positions
-Replaced CDI module
-Replaced spark plugs
---No spark
-Ignition switch and engine stop switch (Black/White-Green from CDI harness) no continuity with ignition switch on and engine stop switch to run
-Exiter coil (Black/Red-Green from CDI harness) 135Ohm
-Pulse generator (Blue/Yellow-Green from CDI harness) 118Ohm
-Ignition coil Primary (Black/Yellow-Green from CDI harness) 1.2Ohm
-Ignition coil secondary NOT tested yet, what are these value measured from?
-Ignition coils measured across poles and I didn't write down the value but not 0 and not 1, will get tonight.
---No spark
-I have wrapped a bare metal wire around the spark plug and twisted it to the engine to verify grounding
-Fusible links are good 20A and 10A
-Took off Engine kill switch and the contacts look clean, even though it is supposed to be an open circuit to start!
---No spark when turning over engine.

New Work:
-Set multimeter to 200V, ran starter motor and got 0 ACV off of Bu/Y and G/W
-Continuity between Bu/Y and G at Ignition pulse generator 115.5 Ohm
-From the Y,Y,Y wires coming from the stator i measured no connection to ground
-Attempted a bypass of the CDI, grounded the wire from the stator to ground, Bl/R to ground. Disconnected wires from stator. Jumped positive batter terminal to postive on ignition coil and grounded the green tab on ignition coil. The wire and tab on the coil sparked when I touched them together. Per sheet it is supposed to spark so it's not the cdi?
--- Had wife also watch for spark after I got the stator put back on the motorcycle
-Continuity from wires going to CDI, Bl/W and Bu/Y and they have 114 Ohms
-Continuity from G out of cdi to ground 1.8 Ohm
-Continuity from Bl/Y from wires to CDI to end of coil 1.9 Ohm
---Tested, no spark
 
#46 ·
I stumbled across this from a Google search, possibly an easier and more reliable way to test your spark plugs
 

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#49 ·
Hey folks, I was having a similar issue. Looking at a wire diagram, I followed the wires to check each major location backwards from the ignition coils using a test light. Looked like this:



Main fuse > Ignition Switch > CDI > Coils


so, testing I found no power to the ignition coils., no power to the cdi unit, yes power to the ignition switch. no power from the black/white wire leaving the ignition switch going toward the cdi unit.



Following this logic, I determined that my ignition switch had gone bad. Taking it off, I saw a giant crack running through the plastic. I don't know if I have the skill to go inside and fix it, but all the connections look good. So, I just purchased a cheapo replacement one on eBay (~$15) and hope that was it.


Best
 
#52 ·
Welcome to the forum, Marshs. Have you read all this thread and followed the suggestions, such as checking the kill switch to be sure it is in the run position?
 
#54 ·
in short, look at a wiring diagram for you year/model and follow each step along the way testing each piece. There aren't that many stops and hopefully you'll find the moment where the break is occurring.

before taking anything apart or doing anything too invasive, i would recommend doing just a visual check along the path for any breaks, disconnects, exposed wire, etc.
 
#56 ·
Welcome to the forum brendanbarmes97!
Although you will get help here, It'd be best if you'd start a new thread for this.
 
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