82 kz250 weak no spark
- 82 kz250l
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82 kz250 weak no spark
07 Oct 2015 14:40 - 07 Oct 2015 14:41
Ok I have a 82 kz250 single cylinder
The bike has a week spark when you first hit the start buton. Just one spark an no spark afterwards....the coil is geting 12volts to both sides of the coil....I'm not to good when it comes to electrical work.....any suggestions?
The bike has a week spark when you first hit the start buton. Just one spark an no spark afterwards....the coil is geting 12volts to both sides of the coil....I'm not to good when it comes to electrical work.....any suggestions?
Last edit: 07 Oct 2015 14:41 by 82 kz250l.
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- Irish Yobbo
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Re: 82 kz250 weak no spark
07 Oct 2015 16:02
So the engine turns over fine, but a very weak spark? My first port of call would be checking all your connections. A bit of corrosion or oil will restrict current, so unplug all your connections leading to the coil and give them a clean.
Next, try another lead. It doesn't need to be the correct lead, or even a lead really, but if you can get some wire to run from the coil to near ground (close enough to spark) and turn it over, it should produce a strong, blue spark. If it does, your coil and wiring up to the coil is fine.
If this still doesn't have a good spark, it's either your coil or your igniter. Clean all your connections to the igniter (they'll be under the chain cover). After that, you can measure the resistance of the coil. I don't know how you test the igniter, but hopefully it's not that - I hear they can be expensive.
Next, try another lead. It doesn't need to be the correct lead, or even a lead really, but if you can get some wire to run from the coil to near ground (close enough to spark) and turn it over, it should produce a strong, blue spark. If it does, your coil and wiring up to the coil is fine.
If this still doesn't have a good spark, it's either your coil or your igniter. Clean all your connections to the igniter (they'll be under the chain cover). After that, you can measure the resistance of the coil. I don't know how you test the igniter, but hopefully it's not that - I hear they can be expensive.
1981 KZ750 LTD
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- 82 kz250l
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Re: 82 kz250 weak no spark
07 Oct 2015 16:28
I just tried everything u said no change. Exsept the one time that it does spark was a strong spark
A little more info on my bike if it helps ...it's a 82 kz250 csr beltdrive an it has the cdi box
A little more info on my bike if it helps ...it's a 82 kz250 csr beltdrive an it has the cdi box
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- Patton
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Re: 82 kz250 weak no spark
07 Oct 2015 17:38 - 07 Oct 2015 17:4082 kz250l wrote: I just tried everything u said no change. Exsept the one time that it does spark was a strong spark
A little more info on my bike if it helps ...it's a 82 kz250 csr beltdrive an it has the cdi box
Perhaps an IC Igniter is being mistaken for a "cdi box."
Here are some examples of various Igniters.
If not already done, would assure that the black/yellow wire to/from the igniter is providing a good ground.
And would also assure that the negative battery cable has a good ground connection where it attaches to the engine.
Good Fortune!

1973 Z1
KZ900 LTD
KZ900 LTD
Last edit: 07 Oct 2015 17:40 by Patton.
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- 82 kz250l
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Re: 82 kz250 weak no spark
07 Oct 2015 20:11
I'll check the black/yellow wire
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- Patton
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- 82 kz250l
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Re: 82 kz250 weak no spark
08 Oct 2015 05:57
That's the same as mine.....the coil ohm out good so I should look in to the ignighter?.....if so is there any test I can do on it?.....thanks for all the help
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- 82 kz250l
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Re: 82 kz250 weak no spark
08 Oct 2015 17:45
Ok for shits an giggles I put an aux ground on the coil .....if I tap the wire to ground it will spark while I'm cranking the engine
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- missionkz
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Re: 82 kz250 weak no spark
08 Oct 2015 20:23 - 08 Oct 2015 20:24
Then your ignition system or point(s) is are never showing a ground to the coils when they're supposed to.
and you do not need to crank the engine to prove that... just turn the key to on or apply 12v to the coils and tap that ground wire to chassis ground.... if you get solid sparks, the coils are good.....
and you do not need to crank the engine to prove that... just turn the key to on or apply 12v to the coils and tap that ground wire to chassis ground.... if you get solid sparks, the coils are good.....
Bruce
1977 KZ1000A1
2016 Triumph T120 Bonneville
Far North East Metro Denver Colorado
1977 KZ1000A1
2016 Triumph T120 Bonneville
Far North East Metro Denver Colorado
Last edit: 08 Oct 2015 20:24 by missionkz.
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- Patton
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Re: 82 kz250 weak no spark
09 Oct 2015 04:49
The coil charges while positive voltage from the battery passes through the coil's primary winding and reaches ground through the points or pick-up module (eg., Dyna-S) or pick-up module plus igniter (eg., stock).
Un-grounding of the primary winding (eg., opening of the points) is the event that causes the coil to fire through the spark plug.
Manually connecting and disconnecting the ground wire from the coil's primary terminal should cause the coil to fire same as when closed points open.
The stock pick-up and igniter are supposed to function together in order to repeatedly ground and un-ground the coil. Which grounding and un-grounding happens via the black/yellow wire to/from the igniter.
Good Fortune!
Un-grounding of the primary winding (eg., opening of the points) is the event that causes the coil to fire through the spark plug.
Manually connecting and disconnecting the ground wire from the coil's primary terminal should cause the coil to fire same as when closed points open.
The stock pick-up and igniter are supposed to function together in order to repeatedly ground and un-ground the coil. Which grounding and un-grounding happens via the black/yellow wire to/from the igniter.
Good Fortune!

1973 Z1
KZ900 LTD
KZ900 LTD
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- 82 kz250l
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Re: 82 kz250 weak no spark
09 Oct 2015 15:31Patton wrote: The coil charges while positive voltage from the battery passes through the coil's primary winding and reaches ground through the points or pick-up module (eg., Dyna-S) or pick-up module plus igniter (eg., stock).
Un-grounding of the primary winding (eg., opening of the points) is the event that causes the coil to fire through the spark plug.
Manually connecting and disconnecting the ground wire from the coil's primary terminal should cause the coil to fire same as when closed points open.
The stock pick-up and igniter are supposed to function together in order to repeatedly ground and un-ground the coil. Which grounding and un-grounding happens via the black/yellow wire to/from the igniter.
Good Fortune!
So I need to look in to the igniter an pickup then Wright?
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