1979 KZ650 wont start - UPDATE***

Hows it going all, new here. I bought a running and driving 1979 kz650 about 5 weeks ago. Rode it around for about a week to make sure everything was good before tearing it down to change mostly looks.

Without getting too deep in the details - after putting her back together, she doesn't want to start. All cylinders getting a nice blue spark, all carbs getting fuel, and compression feels good. Timing looked good, atleast it lined up with the F marks. Is there a way to check if its 180 out? I put fresh gas too.

Some questions:
1)I put these filters on ( 4into1.com/black-foam-chrome-air-filter-pod-39mm-cb750/ ) - I know theres a chance that I'd need to fatten up the jets, but I would think it would atleast start with them. I've tried placing a rag over the filters to restrict flow and still no go.

2) My plug wires are routed as cylinders 1 and 4 from the right coil, and 2 and 3 from the left. I've read this is the correct config somewhere but would like confimation for peace of mind. Also it doesnt matter which wire right? They're wasted spark system?

3) From one of the coils there is a black wire. I know this goes to the poiints - however, the wire into the coil has a connector for two wires. What is the other connection for?

I feel like I'm missing something really simple here and hopefully you guys can point me in the right direction.

Thank you so much!

To check if the points are 180* out look to make sure the little line on the ignition cam is oriented toward the hole in the backplate rather than facing the opposite side of the backplate. Image below shows correct orientation of line and backplate hole. Ed

dexxx wrote: Some questions:

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3) From one of the coils there is a black wire. I know this goes to the poiints - however, the wire into the coil has a connector for two wires. What is the other connection for?
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!

The other connector is probably for the red wire...... If I am understanding your question correctly
See wiring diagram diagrams.kz650.info/wiring/images/KZ650-H2.jpg

One coil will have a green wire and a red wire and the other a black and a red wire. The red wire is for power. Offhand I cant remember which coil gets the green and which gets the black

Thanks for the replies
Imma check the backing plate tomorrow morning.

I rewired the bike with a simpler hardness so the colors wont match before. From what I recall, I have red yellow to power, green to left coil and black to right coil... Which should be correct. But still stumped on that extra black female connector to the right coil

Below is the wiring image for the 1979 K650. Notice each coil should have a red/yellow wire that is connected to the right handlebar control; the red/yellow wires provide power to the coils. There should be a connector that connects the single red/yellow wire from the handlebar to 2 red/yellow wires which then go to the 2 coils. In the diagram I put a red circle around that connector.

The green and black wires control when the coils fire the spark plugs. The coil that is connected to the left hand set of points via the black wire fires plugs 1 & 4; either wire on either plug; whichever length fits best. The coil that is connected to the right hand set of points via the green wire fires plugs 2 & 3; again it doesn't matter which of those wires goes to 2 or 3, which ever length fits best. Ed

Thanks for the reply Ed, the numbers in the diagram will actually help a lot so that I can figure out the wiring/routing to the coils.

As for the red/yellow wire, that is correct on my harness. however the black wire from the points to the 1-4 coil on the right side of the diagram is a little different. From the coil there is the same black wire, but mine has a double female, as opposed to a single. I connected the black wire from the points to one of them, but can't seem to find what used to plug into the other one.

Just guessing, possibly for wire to an electronic tach?

Good Fortune!

Good idea Patton. Makes the most sense of anything I could come up with, and if that's the case then atleast I can just ignore the plug.

Gonna try and start it again later tonight. Hopefully can get her going

Thanks all

GOT IT TO START!!!!
Thanks so much for the help guys...

Turns out its fuel delivery. Sprayed some starter fluid (something I should of done last week but was too lazy to go to the auto store to get some fluid) into the carbs and it started first kick. Only problem now is it wont rev, just idle. Smokes white as well. Obvious answer I'm guessing is running lean. So, gonna jet up. Any reccomendations? Whats stock size? Do I increase both jets for each carb?

THank you all

Would first assure that the carb pilot circuits are perfectly "as new" clean.

Here's one method:




With regard to pilot jet sizing:



Good Fortune!