Accel coil installation
- JimB
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Accel coil installation
19 Apr 2015 21:34
Hello KZrs,
I just wanted to check and see if my thinking was correct. The previous owner put on accel
coils and I think he put them and wrong. He has the pick up wires running to the resistor and then the wires that go to spark plugs also have some resistance. They are suppression wires. I think I should remove one of the resistance paths. I'm thinking about removing the coil wires to the spark plugs and replacing them.
See pictures.
I started looking into this cause my spark at the plugs is very light and often the bike is hard to start.
I have a 1980 KZ 1000 b4 LTD
Jim
I just wanted to check and see if my thinking was correct. The previous owner put on accel
Attachment image-2.jpg not found
coils and I think he put them and wrong. He has the pick up wires running to the resistor and then the wires that go to spark plugs also have some resistance. They are suppression wires. I think I should remove one of the resistance paths. I'm thinking about removing the coil wires to the spark plugs and replacing them.
See pictures.
Attachment image.jpg not found
Attachment image.jpg not found
Attachment image-2.jpg not found
I started looking into this cause my spark at the plugs is very light and often the bike is hard to start.
I have a 1980 KZ 1000 b4 LTD
Jim
Attachment image.jpg not found
Attachment image-2.jpg not found
1978 KZ1000A2, 1980 KZ1000E, 1980 KZ1000B4 LTD
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- missionkz
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Re: Accel coil installation
20 Apr 2015 00:01
Not so sure about the pickup coils vs a control module but the "idea" regardless of how it happens, is to allow a DC path to ground from the 12v supply, through the coils and on to ground to "energize" the coil... when the that path goes open, the coil discharges a giant voltage through the built in step up transformer in the secondary and across the spark plugs.
In the primary circuit with contact points, I don't think it really matters where the resistor is with respect to the primary side of the coil. But I am not so sure about this in a solid state control module supplying the ground path, after sensing crank shaft angle at firing location with a pick up coil.
Me, I would have the resistor in series with the two primary windings of the coil from the +12v side, not the grounded side. Both coils are not energized at the same time so I think just one high wattage resistor feeding the two coils battery voltage is probably a good way to do it,
I made my own out of two 50 watt 4 ohm resistors in parallel for 2 ohms... running two 3 ohm coils with points.
They get much hotter then I expected even though Ohm's Law says the 5 ohms across an average of 13,8v is 2.76 amps.
2.76 amps across my homebrew ballast resistor of 2 Ohms is: +15 watts.
It is VERY uncomfortable to touch this homemade ballast assembly.
Now, the question is, do the spark plug boots also have a 4500-6000 Ohm suppression resistance?
Typically you would probably not run both suppression spark plugs, with suppression plug boot caps.
The wires clearly say suppression type. The caps? How about the spark plugs themselves? Suppression plugs?
So, if you have all three items in there is a good chance that is too much resistance for the coil to push enough current through a plasma of the "spark". Even two of the three in suppression might be too much.
Sorry for the drivel.... Pretty nerdy, huh?
In the primary circuit with contact points, I don't think it really matters where the resistor is with respect to the primary side of the coil. But I am not so sure about this in a solid state control module supplying the ground path, after sensing crank shaft angle at firing location with a pick up coil.
Me, I would have the resistor in series with the two primary windings of the coil from the +12v side, not the grounded side. Both coils are not energized at the same time so I think just one high wattage resistor feeding the two coils battery voltage is probably a good way to do it,
I made my own out of two 50 watt 4 ohm resistors in parallel for 2 ohms... running two 3 ohm coils with points.
They get much hotter then I expected even though Ohm's Law says the 5 ohms across an average of 13,8v is 2.76 amps.
2.76 amps across my homebrew ballast resistor of 2 Ohms is: +15 watts.
It is VERY uncomfortable to touch this homemade ballast assembly.
Now, the question is, do the spark plug boots also have a 4500-6000 Ohm suppression resistance?
Typically you would probably not run both suppression spark plugs, with suppression plug boot caps.
The wires clearly say suppression type. The caps? How about the spark plugs themselves? Suppression plugs?
So, if you have all three items in there is a good chance that is too much resistance for the coil to push enough current through a plasma of the "spark". Even two of the three in suppression might be too much.
Sorry for the drivel.... Pretty nerdy, huh?
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
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- Patton
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Re: Accel coil installation
20 Apr 2015 07:01
Is it a points ignition or an electronic ignition.
If electronic, is it a stock igniter style or aftermarket such as Dyna-S?
Do the Accel coils have same resistance as stock coils?
Does the stock wiring include a resistor in the battery-positive feed to the coils?
Does it appear that the resistor was added to the stock wiring when the Accel coils were installed?
Are stock NGKB8ES spark plugs fitted?
Or, are non-stock "R-type" (resistance type) spark plugs fitted, such as NGKBR8ES?
The secondary loop (secondary winding, plug wires, caps, plugs, and metal engine head) is okay without any resistance component.
The factory uses resistance plug caps as the single resistance component in the secondary loop for the purpose of reducing electronic interference in things such as radio noise.
Any more than one resistance component weakens the spark.
For example, resistance plug wires plus resistance plug caps is too much resistance.
Resistance R-type plugs should not used together with resistance wire or resistance caps.
Good Fortune!
If electronic, is it a stock igniter style or aftermarket such as Dyna-S?
Do the Accel coils have same resistance as stock coils?
Does the stock wiring include a resistor in the battery-positive feed to the coils?
Does it appear that the resistor was added to the stock wiring when the Accel coils were installed?
Are stock NGKB8ES spark plugs fitted?
Or, are non-stock "R-type" (resistance type) spark plugs fitted, such as NGKBR8ES?
The secondary loop (secondary winding, plug wires, caps, plugs, and metal engine head) is okay without any resistance component.
The factory uses resistance plug caps as the single resistance component in the secondary loop for the purpose of reducing electronic interference in things such as radio noise.
Any more than one resistance component weakens the spark.
For example, resistance plug wires plus resistance plug caps is too much resistance.
Resistance R-type plugs should not used together with resistance wire or resistance caps.
Good Fortune!

1973 Z1
KZ900 LTD
KZ900 LTD
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- loudhvx
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Re: Accel coil installation
21 Apr 2015 16:11Sorry for jacking this thread,...missionkz wrote: ...I made my own out of two 50 watt 4 ohm resistors in parallel for 2 ohms... running two 3 ohm coils with points.
They get much hotter then I expected even though Ohm's Law says the 5 ohms across an average of 13,8v is 2.76 amps.
2.76 amps across my homebrew ballast resistor of 2 Ohms is: +15 watts.
It is VERY uncomfortable to touch this homemade ballast assembly.
If you are using a Dyna III ignition (or Dyna S), both coils are energized most of the time. That would change your calculation a bit, and might account for the extra heat.
1981 KZ550 D1 gpz.
Kz550 valve train warning.
Other links.
Kz550 valve train warning.
Other links.
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- missionkz
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Re: Accel coil installation
21 Apr 2015 16:21Yes.. and I stand corrected then as the two in parallel would be 1.5 ohms in series with my homebrew 2 ohm ballast, or 13.8v/3.5 ohms = <4 amps!loudhvx wrote:Sorry for jacking this thread,...missionkz wrote: ...I made my own out of two 50 watt 4 ohm resistors in parallel for 2 ohms... running two 3 ohm coils with points.
They get much hotter then I expected even though Ohm's Law says the 5 ohms across an average of 13,8v is 2.76 amps.
2.76 amps across my homebrew ballast resistor of 2 Ohms is: +15 watts.
It is VERY uncomfortable to touch this homemade ballast assembly.
If you are using a Dyna III ignition (or Dyna S), both coils are energized most of the time. That would change your calculation a bit, and might account for the extra heat.
So 4a^2 x 2ohms = 32 watts!
Thanks!!
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
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