Poor spark and spark between contact breakers.

I have restored a kawasaki z650 and i simply cant get it to start! I am a mechanical and technical engineer but this is starting go get me frustrated!
The engine have been completly rebuild all tolerances are met and there should be no problem starting it.

Info:
It is the first z650 from 77 which need a batteri for the non permanent magnet in the rotor at the generator.
The wirering harness on the bike is from a new model with a permanent magnet generator. But i dont think this have anything to do with why it can not start?

My problem is
1. On the ignition there is a spark between the contack breakers
2. The spark on the plug is not continuous

I thought if was the condensators so i tried to measure them out. But they both seem to be okay with the value 0,252uF

Have anyone had this problem?

Could the advancer unit be 180 degrees off?
Is there cylinder compression?
Any popping or backfiring?

As z1kzonly says, the advancer can be 180 out if you took it apart to clean etc.

Also, you should be aware, the coils spark two plugs at a time, so in order to see spark you have to make sure both plug wires from the coil have a path to the engine.

The engine has gone through total renovation and everything is "very clean"
I have checked the advancer unit and there are compression. there is combustion a few times. when i checked the sparkplugs the otherplug igniting at the same time was mounted in the engine and the one i checked on the engine so i could see the spark.

But why is there a spark between he contact breakers when the condensators is ok? bad minus?

Points will always have a little bit of sparking even when everything is working fine.
If there is a lot of sparking, then it could be a condenser. Sometimes a condenser can fail under high voltage, but you cannot detect that just by measuring with a capacitance meter or ohm meter.

But if one plug sparks, and not the other plug, then it's a plug wire problem, or resistor cap problem, or even a coil problem.
When checking for spark, You should check both sides to make sure they both spark or fail. You can check that by taping two plugs together threads-to-threads. Then connect the plug wires to the plugs. They should both spark. In this test, they don't need to contact the engine because touching the plugs together completes the path.

The 1977 KZ650 models need a battery to run, just as you pointed out. This is because the 1977 KZ650 uses a field coil charging system. You have a battery, but you state you are not using a 1977 KZ650 wiring harness. So by using the wrong wiring harness it is doubtful that you are energizing the field coil.

If it was my bike I would install a correct wiring harness even if I had to build one from scratch. Below is a link to all KZ650 wiring diagrams. Notice that in the diagrams for the 1977 models (KZ650-B1 and KZ650-C1) the charging system is totally different than any other models, and consequently, the wiring harnesses and their connections are different. So using a different wiring harness will not work with the 1977 charging system and will affect the engine starting. Ed

diagrams.kz650.info/wiring/WiringDiagrams.htm

Ah okay i will try new condensators then! (did not know they could be defect anyway) both the plugs spark when doing the test (i did it individually) but i will try the one with plug to plug to compare them!

I have the B1 components connected to the newer wiringharness and combined it. But i can not state if it charges before it runs. It should start with a battery connected though, the plugs spark and it has the current it needs?

I don't want to overstate the condensers as the problem. It would be uncommon for that to be the problem, especially for both ignition circuits. But it also cannot be ruled out.

It would more likely be a voltage issue or even a setup issue on the points. (The most likely issue would be the rotor being installed backwards on the advancer, but you've checked that.)

As Ed points out, the newer harness wouldn't have the necessary wires for the older alternator and regulator and rectifier.
Unless you are saying you combined parts of the old harness with the new harness. Then it could work.
Either way, this should not really affect the ignition as long as the battery is decent and charged.

I'd try reversing the power leads to the coils.Left to right, right to left.
Steve

If not already done, would assure that the ignition coil firing the two inside spark plugs has a primary terminal connected to the signal wire (usually green) that's coming from the 3 o'clock set of points, And that the ignition coil firing the two outside spark plugs has a primary terminal connected to the signal wire (usually black) that's coming from the 9 o'clock set of points.

Good Fortune!

I have connected the ignition the right way and got a mechanic to help, but sadly it still did not start.. I have ordered a new set of condensers and will try to measure the voltage between the coils and make the plug against plug test and return with a update.

Thank you for the help so far

Svendsen wrote: ... both the plugs spark... the plugs spark....

Svendsen wrote: ... connected the ignition the right way....

Svendsen wrote: ... there is combustion a few times... could see the spark....

Perhaps the ignition system is okay.

combustion a few times -- indicates loss thereafter of fuel mixture inside the combustion chamber.
Perhaps "fuel starvation" (for whatever reason) is the culprit.

Does application of starting fluid result in longer more continuous combustion?

For the record, proper cold starting procedure is with choke applied and throttle fully closed (don't even touch the grip).
If no start, would quickly remove and examine a spark plug to determine whether there's gasoline on the business end of the plug.

Might be time to check the carb pilot circuits to determine whether there's blockage preventing fuel mixture from reaching the carb bore.

Good Fortune!