1978 KZ650D1(sr) coils ?
- gargoyle
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1978 KZ650D1(sr) coils ?
28 May 2008 21:06 - 28 May 2008 21:11
Hi
I'm in the process of rebuilding a 1978 KZ650sr that i just got. The guy I got the bike from never got it running. Can any one tell me if these are the stock coils/wires/caps for my bike. Primary resistance is 4.4ohms secondary is 23.7 Kohms. both coils measure the same. Manual says spec is 3.2-4.8 ohms (primary) and 10.4-15.6 Kohms (secondary). To me it looks like some one replaced the plug caps. Looks like there are 3 different styles. What are the large black cylinders behind the caps on wires 1,2, & 4.
Does the high secondary resistance mean that they are dead or dying?
Thanks in advance.
I'm in the process of rebuilding a 1978 KZ650sr that i just got. The guy I got the bike from never got it running. Can any one tell me if these are the stock coils/wires/caps for my bike. Primary resistance is 4.4ohms secondary is 23.7 Kohms. both coils measure the same. Manual says spec is 3.2-4.8 ohms (primary) and 10.4-15.6 Kohms (secondary). To me it looks like some one replaced the plug caps. Looks like there are 3 different styles. What are the large black cylinders behind the caps on wires 1,2, & 4.
Does the high secondary resistance mean that they are dead or dying?
Thanks in advance.
1978 KZ650sr
Woodstock, Ontario
Canada
Woodstock, Ontario
Canada
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Last edit: 28 May 2008 21:11 by gargoyle.
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- Patton
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Re: 1978 KZ650D1(sr) coils ?
29 May 2008 04:22
Thinking coils are okay. Higher ohm secondary could be added resistance of plug wires and caps.
looks like some one replaced the plug caps -- YES it does.
large black cylinders behind the caps on wires 1,2, & 4 -- maybe wire length extensions or possibly some sort of in-line resistor.
Am guessing the wires are old and hard, and probably leaking. Often the permanently attached wires are the first things to go bad.
Would visibly inspect for spark at plug tip, hoping for a good quality spark.
Might consider replacing plug wires with Dyna solid core wires from Z1E which come already equipped with caps:
New Plug Wires
And probably also need plug wire splicers also available from Z1E: Plug Wire Splicer
Good Luck!
looks like some one replaced the plug caps -- YES it does.
large black cylinders behind the caps on wires 1,2, & 4 -- maybe wire length extensions or possibly some sort of in-line resistor.

Am guessing the wires are old and hard, and probably leaking. Often the permanently attached wires are the first things to go bad.
Would visibly inspect for spark at plug tip, hoping for a good quality spark.
Might consider replacing plug wires with Dyna solid core wires from Z1E which come already equipped with caps:
New Plug Wires
And probably also need plug wire splicers also available from Z1E: Plug Wire Splicer
Good Luck!

1973 Z1
KZ900 LTD
KZ900 LTD
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- gargoyle
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Re: 1978 KZ650D1(sr) coils ?
29 May 2008 06:16
Yes upon further inspection the higher resistance is ok. I missed the part in the Kawasaki manual that says to take the caps off when measuring the resistance. The Clymer manual says that 23k ohm is spec for the caps on.
This brings up another question. Why do you want resistors in the wires. Don't you want all of the voltage drop to be across the plug gap. Adding a resistor in line would split the voltage between the two. Is it to limit current flow?
This brings up another question. Why do you want resistors in the wires. Don't you want all of the voltage drop to be across the plug gap. Adding a resistor in line would split the voltage between the two. Is it to limit current flow?
1978 KZ650sr
Woodstock, Ontario
Canada
Woodstock, Ontario
Canada
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- loudhvx
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Re: 1978 KZ650D1(sr) coils ?
29 May 2008 12:37
It's to reduce radio interference. You only want resistor caps, or resistor wires, or resistor plugs, but not a combination.
1981 KZ550 D1 gpz.
Kz550 valve train warning.
Other links.
Kz550 valve train warning.
Other links.
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