'76 kz750

Hello all, New to Kawasaki here. I had the chance to buy a 76 KZ750 for 100 dollars. grabbed it, got it in the garage I took apart both carbs and cleaned with carb dip and reinstalled. now i am working on wiring. the bike doesn't have any lights, so i am trying to get power to all the right places without burning anything up. i have attached the diagram i have been using for reference. the place i am having trouble is the wiring for the regulator/rectifier. it looks like the green wire out of the regulator is attached to the generator through a resistor? is that correct??? if so what size resistor do i need? on another note, the yellow/red wire from the right hand grip looks like it should send power to the coil. i applied 12V to the brown wire because i thought it was the power feed for that hand grip. right now i am just trying to get it to run so i can see if its worth putting more money into this project. Using my powerprobe and applying 12v to the signal side of the coil cranks the motor just fine, but i just not getting any spark. thanks in advance for any assistance!

I don't know what differences (if any) there are, but the link below show the wiring diagram for the 1976 KZ650-B1. Ed

kz750twins.com/wp-content/uploads/2009/07/kz750b1.jpg

Thanks for the quick reply 650ed! I checked out the diagram you attached, and it appears to be the same as the one i am using currently. yours is a more clear picture though, so i think i am going to adopt yours for use!

Hello, bonneman97se, and WELCOME to KZr!

With the ignition switched ON, what is voltage at the female connector on the red/yellow wire going to the coil primary?



Given adequate power to the coil primary, the reason for lack of spark is likely related to functionality of the coil, or the secondary loop, or the points.



Good Fortune!

I am not getting any voltage on the red/yellow wire, and i think it is because i am missing the engine run/stop switch. so i can see the open terminals on the right grip. should i just take the 12v that i am using to feed the right grip and just feed it right to the coil? (using the red/yellow wire) i am trying to get all the wiring sorted before actually starting it because i dont want to fry the stator/regulator/rectifier.

As I interpret the wiring diagram, the brown wire at the right handlebar is fed power from the ignition switch and it in turn provides power to the yellow/red wire when the right handlebar kill switch is in the "Run" position. This actually is the normal position for the kill switch. The yellow/red wire then feeds power to the coil. So, since the brown wire is only "hot" when the ignition switch is "ON", and since under normal conditions it is connected through the kill switch to the yellow/red wire, I would think connecting that brown wide directly to the yellow/red should be ok as long as you recognize that you will not have a kill switch function. Ed

alright thanks 650ed and patton! i am just going to try a jumper to the coil and use my powerprobe to crank the engine over and see what happens. do i just need to hook the green wire from the regulator to the brown wire coming out of the case? all of loudhvx's diagrams say the green goes to the field coil, but im just not sure if the field coil is just on the other end of the brown wire???

For testing toward obtaining spark at the plugs, could use a hot wire from the battery+ terminal running to the coil primary .
Should be using a good, fully charged battery.
Remember to disconnect the hot wire after testing.

Also, would assure integrity of the connection where the negative battery cable attaches to the engine.

Good Fortune!

As known, the ignition system is separate from the charging system.

With a good, fully charged battery, and no charging components whatever (i.e., alternator, rectifier, regulator) , the bike should perform normally until the battery runs down.

Would just hot wire the coil via the red/yellow wire, and see if the engine will crank and run.

Good Fortune!

alright guys, just did the mentioned. ran a wire from 12v right to bullet connector on coil and cranked engine nothing, i pulled both plugs and grounded while cranking engine no spark on either side. the coil is showing 3 ohms of resistance on my powerprobe. i think the coil is good, i assume i should check points/condenser next?

also just so its stated it is a brand new battery sitting at 12.7V engine cranks decently, just no spark, even with jumper wire.

Any break within the secondary loop will prevent spark on both plugs.
A shorting plug wire is one of the possible suspects.

Would check connections of plug wires at coil towers (unless permanently attached), plug wires to plug caps, and plug caps to plugs.

It might help to slightly trim off a bit of the plug wires to gain a better connection to the caps.

If in doubt about the plugs, would use new factory spec spark plugs.

Could ohm-test the secondary loop, measuring resistance between the caps, or between ends of plug wires removed from plug caps.
The following diagram is for illustration only -- DON'T CUT the plug wires. :pinch:




Here's a better illustration:




Given adequate voltage to a functional coil, and being satisfied as to integrity of the secondary loop, would then assure that the points are functional.

With reference to the points, closed contacts provide a ground for the coil's primary wiring (while the coil "charges").
When the contacts open, the ground is broken, which causes the charged coil to fire (discharge) through the secondary loop.

Good Fortune!

If need be, the secondary loop may also be tested for ability to produce spark at the plugs without relying on functionality of the points.

With the red/yellow wire furnishing power to the coil, the "green" wire from the coil primary terminal may be manually grounded and ungrounded to produce firing through the secondary loop.

Good Fortune!