1976 cb750 no spark

[ford_fan]

i have power from the ignition through the coils and down to the contact points but still am not getting spark im out of ideas plz help we replaced the coils last year have cleaned the frame ground it did run abbout 2 yrs ago has sat since it does crank

[TOOLS1]

Is this on all 4 cylinders, 2 cylinders, or just 1? However just a thought, is the kill switch on the throttle in the off position? Also, are you removing sparkplugs, and grounding them to the engine when checking for spark?
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[ford_fan]

theres no spark on all four and thats with the kill switch in the on or run posistion

[TOOLS1]

It is very rare that you would loose spark at all 4 sparkplugs at once and still have voltage to the points. Are the points opening? They should be gaped at 0.013-0.015. It the breaker cam rotating to open the points? Is there a wire (like the one's on the condensers) grounding out? I one had a bike that had a small section of bare wire coming out of the condensers that was grounding out the ignition and keeping it from running.
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[ford_fan]

i was wondering if that part behind contact points might have have been bad that and the point cause wasnt sure if they were opening just didnt know what it was called. just thought it was odd that it ran one year n the next nothing but thinking back it was getting harder to start

[ford_fan]

ive tried looking one up and cant seem to find one can find contact points but cant seem to find a breaker cam

[TOOLS1]

If the breaker cam is turning freely on the shaft, moving the advancer weights, it should be good. The thing that would make it fail would be the alingment pin on the crank, or the bolt that holds it on the end of the crank coming loose, and not holding it to the end of the crankshaft. However it is most likely that the wires to the points, either from the coils, or the condensers are grounding out. They are insulated on onto the mount at the points so that they only make contact with the half of the point that moves. It for any reason the wires make connection with the other half of the point, they will ground out, and not fire the plugs.
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[ford_fan]

so a new contact point assembly should do the trick?

[TOOLS1]

Maybe, maybe not. Are yours adjusted properly? Are they opening at the correct time? Are the wires connected properly, so that they are not grounding on the point plate, or against the stationary side of the points? The little bolt that the wires attache to the points with has a little insulator piece on it to insulate the bolt against the stationary side of the points, and it is easy to attach the wires on the wrong side of the insulator, or even loose the insulator. And easy way to tell if you have the wire grounded is to hook a test light to the + on the battery, and then place the test light on the end of the bolt that the wires attach to. If the test light does not come on when the points are open, the wires are grounded somewhere. The light should go off when the points close though.
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