No spark


Information and questions on GL1000 Goldwings (1975-1979)
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Hawkengl1000
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Motorcycle: 1978 gl1000

No spark

Post by Hawkengl1000 »



So I've got a 1978 gl1000. Out a new battery on it after cam belts changed, oil change, new spark plugs. So any way new spark plugs but no spark. Taken kill switch apart and the power going through is on about 7 volts but battery at 12 volts. Taken the two leads of the coils and they also only read about 7 volts. Any ideas


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dingdong
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Re: No spark

Post by dingdong »

The 7 volts is normal in the run position. There is a ballast resistor in the circuit (mounted to the left coil) that lowers the primary voltage at the coils. However when the starter button is pressed the voltage should be 12 volts as the ballast is by-passed for start. Do you have a wiring diagram?
Hawkengl1000
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Re: No spark

Post by Hawkengl1000 »

I do but I don't understand them and tbh. So it's probably just coils if I'm getting. Should the power increase when I try starting it. Like I said I'm getting no spark but 7 volts at all times
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Maz
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Motorcycle: 1975 GL1000K1
1976 CB500T
1979 CB750L
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Re: No spark

Post by Maz »

Hawkengl1000 wrote:I do but I don't understand them and tbh. So it's probably just coils if I'm getting. Should the power increase when I try starting it. Like I said I'm getting no spark but 7 volts at all times
As Dingdong said, when you press the start button, you should get 12v at the coils, as the ballast resistor is bypassed (to give you full 12v / fatter spark while cranking). If you are getting the 7v/12v feed to the coils, check the Blue and Yellow wires, which go to ground, via the ignition points. Are they connected at the coils and the points?

Maz
Ironically, Common Sense is the LEAST common of all senses!
Hawkengl1000
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Joined: Tue Jan 10, 2017 5:34 am
Location: England
Motorcycle: 1978 gl1000

Re: No spark

Post by Hawkengl1000 »

Thank you for your reply. I will check them again tomorrow. When I opened the kill switch to clean it and I tested the voltage going through that and that was at 7 volts too. The bikes not in the best condition and it has electrical tape all over the place. I would have assumed the volts running through the kill switch would be 12v but I'm not sure what would cause it to be less except the battery but the battery is good.
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Maz
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Re: No spark

Post by Maz »

I think the state of the wiring may be very relevant! When you measured the battery volts, I assume you measured directly across the battery terminals? Try measuring between the + terminal and various points on the frame and engine. You should still be measuring battery voltage. If you measure less, you have bad earth (ground) connections somewhere. There could also be corrosion in the multiple spade / bullet connections throughout the wiring loom. All of these will need cleaning and checking.

Maz
Ironically, Common Sense is the LEAST common of all senses!
Hawkengl1000
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Re: No spark

Post by Hawkengl1000 »

Thank you I will definitely try that tomorrow and let you know how I get on.

Thank you again.
Hawkengl1000
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Re: No spark

Post by Hawkengl1000 »

Hi guys I just want to thank you for the your help so far I have checked the earthing and that is all good. I should be ashamed really as I am a motorcycle recovery driver not a mechanic by trade but still these things I should know. But it's been a big learning experience.

I opened up where the point breaker is and the points were pretty bad one was stuck and when released wouldn't spring back but have adjusted them. The wires between the breaker points and condenser and up to the the coils have been cut and just twisted together.

I am now recharging the battery and I'll go from there.
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Stu_O
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Re: No spark

Post by Stu_O »

Hawkengl1000 wrote:Hi guys I just want to thank you for the your help so far I have checked the earthing and that is all good. I should be ashamed really as I am a motorcycle recovery driver not a mechanic by trade but still these things I should know. But it's been a big learning experience.

I opened up where the point breaker is and the points were pretty bad one was stuck and when released wouldn't spring back but have adjusted them. The wires between the breaker points and condenser and up to the the coils have been cut and just twisted together.

I am now recharging the battery and I'll go from there.
For sure, get all of that wiring sorted. I'm working on a '78 right now for a customer with similar symptom as yours. No spark while cranking, but 7 volts measuring static. As the guys have told you, there's a bypass circuit that allows 12V straight to the coils when the start button is pressed. The current has to pass through a silicon diode. which on the '78 and '79 is hidden behind the electrical junction box on the left side...behind the left shelter half. The clutch diode is mounted right alongside it. On this bike, corrosion had gotten to the diode contacts and their socket terminals, which prevented current flow when the start button was pressed. The other diode was just as bad, so the bike couldn't be started in gear with the clutch lever squeezed in.

Unplug the red, black, and white connectors from the junction box, then remove the two bolts to slide the box and its bracket left, then outward to expose the diodes mounted on the backside. Unplug the diodes and clean their contacts down to bare metal, then test the diodes with an ohm meter. If they were really crusty, you'd probably need to replace the socket terminals as well, and make sure the bare wire is clean before crimping on new terminals. I can post pics for you later if you need them.

Stu O
Hawkengl1000
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Re: No spark

Post by Hawkengl1000 »

Stu_O wrote:
Hawkengl1000 wrote:Hi guys I just want to thank you for the your help so far I have checked the earthing and that is all good. I should be ashamed really as I am a motorcycle recovery driver not a mechanic by trade but still these things I should know. But it's been a big learning experience.

I opened up where the point breaker is and the points were pretty bad one was stuck and when released wouldn't spring back but have adjusted them. The wires between the breaker points and condenser and up to the the coils have been cut and just twisted together.

I am now recharging the battery and I'll go from there.
For sure, get all of that wiring sorted. I'm working on a '78 right now for a customer with similar symptom as yours. No spark while cranking, but 7 volts measuring static. As the guys have told you, there's a bypass circuit that allows 12V straight to the coils when the start button is pressed. The current has to pass through a silicon diode. which on the '78 and '79 is hidden behind the electrical junction box on the left side...behind the left shelter half. The clutch diode is mounted right alongside it. On this bike, corrosion had gotten to the diode contacts and their socket terminals, which prevented current flow when the start button was pressed. The other diode was just as bad, so the bike couldn't be started in gear with the clutch lever squeezed in.

Unplug the red, black, and white connectors from the junction box, then remove the two bolts to slide the box and its bracket left, then outward to expose the diodes mounted on the backside. Unplug the diodes and clean their contacts down to bare metal, then test the diodes with an ohm meter. If they were really crusty, you'd probably need to replace the socket terminals as well, and make sure the bare wire is clean before crimping on new terminals. I can post pics for you later if you need them.

Stu O
I know the clutch one is ok as did leave it in gear once.
Hawkengl1000
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Re: No spark

Post by Hawkengl1000 »

Ok so just a little update. So battery back on and so the breakers are moving and back and fourth ok. I checked the voltage on the wire that come of breaker points and before the starter is pushed I get 9 volts and after button pushed it drops to 7 volts. I'll update more when I get a chance. My garage has no electric
Hawkengl1000
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Re: No spark

Post by Hawkengl1000 »

Hi guys I want to say thank you so much for your help. I cleaned breaker points, checked and cleaned connections, checked coils, trimmed ht leads, took spark plug caps apart and serviced it. Finally have a spark. I didn't understand first instructions given but after a a few videos and some research I got it. Thanks guys people like you that make it easier and cheaper for people like me.
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Maz
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Motorcycle: 1975 GL1000K1
1976 CB500T
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1993 Suzuki GS500E

Re: No spark

Post by Maz »

Hawkengl1000 wrote:Hi guys I want to say thank you so much for your help. I cleaned breaker points, checked and cleaned connections, checked coils, trimmed ht leads, took spark plug caps apart and serviced it. Finally have a spark. I didn't understand first instructions given but after a a few videos and some research I got it. Thanks guys people like you that make it easier and cheaper for people like me.
Glad you got that one sorted. I did post another reply about the 9v being measured at the contact breaker wires (blue / yellow) being due to the resistance of the coils ,etc, but it has disappeared! No problem, you have a spark so we should have another 'Wing touring British shores soon?
Maz
Ironically, Common Sense is the LEAST common of all senses!
Hawkengl1000
Posts: 31
Joined: Tue Jan 10, 2017 5:34 am
Location: England
Motorcycle: 1978 gl1000

Re: No spark

Post by Hawkengl1000 »

Yes I definitely hope so. I'm not doing a full restore yet as I'd like to just have her on the road rather then sat in my garage for a year in bits. Thanks again guys
Hawkengl1000
Posts: 31
Joined: Tue Jan 10, 2017 5:34 am
Location: England
Motorcycle: 1978 gl1000

Re: No spark

Post by Hawkengl1000 »

Maz wrote:
Hawkengl1000 wrote:Hi guys I want to say thank you so much for your help. I cleaned breaker points, checked and cleaned connections, checked coils, trimmed ht leads, took spark plug caps apart and serviced it. Finally have a spark. I didn't understand first instructions given but after a a few videos and some research I got it. Thanks guys people like you that make it easier and cheaper for people like me.
Glad you got that one sorted. I did post another reply about the 9v being measured at the contact breaker wires (blue / yellow) being due to the resistance of the coils ,etc, but it has disappeared! No problem, you have a spark so we should have another 'Wing touring British shores soon?
Maz
Hi maz do you live in Britain too?
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Maz
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Motorcycle: 1975 GL1000K1
1976 CB500T
1979 CB750L
1990 Yamaha FJ1200
1993 Suzuki GS500E

Re: No spark

Post by Maz »

I sure do. Bexley, Kent.
Maz


Ironically, Common Sense is the LEAST common of all senses!
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