So I bought some aftermarket coils on ebay from "DB Electrical" the primary wires are yellow and black but neither the coil or the wires are marked + or -. The coils came with no instructions or anything. Can anyone help me identify or tell me how too identify which of the wires is + and which is negative? Here is the ebay link to the exact coils I purchased...
DB Electrical Coils? Primary wires arent marked?
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DB Electrical Coils? Primary wires arent marked?
1979 XS1100
1976 KZ750 Twin (Project)
2015 Street Bob
1978 MX80
1975 CB550 (Project)Tags: None -
If those coils are for your listed 79XS1100, they are incorrect ohm coils. The 79 XS1100 uses 1.5ohm coils. The ones your showing are 3ohm coils..
81H Venturer1100 "The Bentley" (on steroids) 97 Yamaha YZ250(age reducer) 92 Honda ST1100 "Twisty"(touring rocket) Age is relative to the number of seconds counted 'airing' out an 85ft. table-top. -
Yes I bought the 3ohm and will disable the resistor1979 XS1100
1976 KZ750 Twin (Project)
2015 Street Bob
1978 MX80
1975 CB550 (Project)Comment
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They're wasted spark coils. The Secondary voltage fires one spark plug with normal polarity center electrode to ground strap, the other plug fires reverse polarity ground strap to electrode so the Primary polarity doesn't really matter.
If there are no markings on the coils themselves at the terminals I'd make the Yellow wire the positive and the Black wire negative but it's your bike, pick a color and tell yourself it's the positive lead and the other one's negative.
Just for grins, swap the two wires every few thousand miles so the two spark plugs will wear evenly.-- Scott
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2004 ST1300A: No name... yet
1982 XJ1100J: "Baby" SS Brakes, '850 FD, ACCT
1980 XS1100G: "Columbo" SS Brakes, '850 FD, ACCT
1979 XS1100SF: "Bush" W.I.P.
1979 XS1100F: parts
2018 Heritage Softail Classic 117 FLHCS SE: "Nanuk" It's DEAD, it's not just resting. It is an EX cycle.
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Fair enough, i will do as advised short of changing the wires for plug wear, lol...1979 XS1100
1976 KZ750 Twin (Project)
2015 Street Bob
1978 MX80
1975 CB550 (Project)Comment
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Be bold and drive the pettifoggers nutz, use two different color wires for each of the two coils.-- Scott
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2004 ST1300A: No name... yet
1982 XJ1100J: "Baby" SS Brakes, '850 FD, ACCT
1980 XS1100G: "Columbo" SS Brakes, '850 FD, ACCT
1979 XS1100SF: "Bush" W.I.P.
1979 XS1100F: parts
2018 Heritage Softail Classic 117 FLHCS SE: "Nanuk" It's DEAD, it's not just resting. It is an EX cycle.
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Ask
Website seems to invite questions. I would send a message and ask them.1981 XS1100H Venturer
K&N Air Filter
ACCT
Custom Paint by Deitz
Geezer Rectifier/Regulator
Chacal Stainless Steel Braided Brake Lines
Chrome Front Rotor & Caliper Covers
Stebel Nautilus Horn
EBC Front Rotors
Limie Accent Moves On In 2015
MikeComment
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T.C.T. C. Gresham
81SH "Godzilla" . . .1179cc super-rat.
79SF "The Teacher" . . .basket case!
History shows again and again,
How nature points out the folly of men!Comment
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The inexpensive inductive coils for wasted spark are not sensitive to Primary polarity. If the coils are marked it's so the techies don't get lost while they're trying to trace ignition wires and earn a living, not because the coils or the spark plugs really care about polarity.
Remember, the electrons have to complete the circuit through the cylinder head too, not just the coil. Here are the possible 4 cylinder wasted spark electrode polarities so the head doesn't run out of electrons for the ignition system:
Street and Circle Track (NASCAR)
1(+) 2(+) (-)3 (-)4
Antipodean Street and Circle Track
1(-) 2(-) (+)3 (+)4
Moto GP Weave
1(+) 2(-) (+)3 (-)4
Antipodean Moto GP Weave
1(-) 2(+) (-)3 (+)4
-- Scott
_____
♬
2004 ST1300A: No name... yet
1982 XJ1100J: "Baby" SS Brakes, '850 FD, ACCT
1980 XS1100G: "Columbo" SS Brakes, '850 FD, ACCT
1979 XS1100SF: "Bush" W.I.P.
1979 XS1100F: parts
2018 Heritage Softail Classic 117 FLHCS SE: "Nanuk" It's DEAD, it's not just resting. It is an EX cycle.
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Thank you everyone for your replies. I got it all figured out. I assumed the polarity didn't matter but I was having some backfiring issues. I was tired and had been working on it most of the day so I came inside, posted my query and shortly there after went to sleep. I went out this morning and traced the issue to a loose plug cap I over looked. I recounted the coils, rechecked all the wires and she fired right up. Purrs like a kitten now. I will attempt to post a video here shortly.1979 XS1100
1976 KZ750 Twin (Project)
2015 Street Bob
1978 MX80
1975 CB550 (Project)Comment
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