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Author Topic: In need of some wiring help on 76 750  (Read 1120 times)

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Offline krazyk

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In need of some wiring help on 76 750
« on: January 23, 2011, 01:38:06 PM »
I M working on trying to straighting out the wiring on a 76 750. previous owner cobbled up a a push button starter I replaced the left side control. It spins over now buy stock start button but I M not getting any spark through plug wires. I have power on both the Yellow wire and the Blue wires going into coil but don't seem to have any thing coming from coils any subjections. What is the best way to trouble shoot coil? Also would like to upgrade the system. can I upgrade the rectifier etc. I have a CB900C parts bike
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bollingball

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Re: In need of some wiring help on 76 750
« Reply #1 on: January 23, 2011, 02:04:15 PM »
Try taking off the plug caps trim off 1/4 to 1/2 inch of wire put caps back on and test again.
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Offline krazyk

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Re: In need of some wiring help on 76 750
« Reply #2 on: January 23, 2011, 02:20:21 PM »
Removed plug cap and stuck test light in and no power. If I had spark it should have lit test lite up should'nt it
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bollingball

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Re: In need of some wiring help on 76 750
« Reply #3 on: January 23, 2011, 02:39:49 PM »
Better be one hell of a test light do you know what kind of voltage your are working with? Trim the wires put caps on put plugs in cap and ground plug on the engine and look for spark. is your KILL sw. off
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bollingball

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Re: In need of some wiring help on 76 750
« Reply #4 on: January 23, 2011, 02:46:17 PM »
Well if you have 12 volts at the coils that takes care of the kill sw. but check sometime while working it get moved and forgotten.Just before checking for stark make sure you still have 12 volts on primary of coils. Has it ran lately.
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bollingball

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Re: In need of some wiring help on 76 750
« Reply #5 on: January 23, 2011, 03:07:30 PM »
If still no spark check coil with ohm meter. take off those 12 volt wires and check primary side if stock should be about 5K ohms secondary plug wires with caps off from one plug wire to the other on same coil should be about 15 K ohms
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Offline BrianAdair

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Re: In need of some wiring help on 76 750
« Reply #6 on: January 23, 2011, 03:09:30 PM »
you say you have power on the yellow and blue wires? They come from the points, I thought the black/white wire was power, with the ks in the run position, and the blue and yellow just sent the spark signal?
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Offline Spanner 1

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Re: In need of some wiring help on 76 750
« Reply #7 on: January 23, 2011, 03:34:04 PM »
Having power ( + 12v) on the blue and yellow wire at the points proves 2 things; i.e. that the coils are getting power on the black/white wire and that the coil primary is good........ however 0 voltage must be present when you turn the crank and each point closes. If the voltage stays on bl. and yel. with a full rotation of the points cam then the points are not closing or ( more common ) there is a 'film' on the points causing them to fail to conduct said voltage to ground.... clean 'em up good and try again  :)
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