81 KZ750H LTD No spark

Good afternoon all, new to me Kz750H, never seen it running. Just rebuilt the carbs and was excited for the first time running it. Turned over, nothing. I start to check spark by grounding the plug on the block and no spark on cylinder 1, same for cylinder 2. I pull the coil on the clutch handle side. 2.7ohms across the coil pins. 11.7v & 11.2v from the wires. I check the throttle side and I get the exact same readings. What other diagnostics can I run to narrow down my issue? What tests can I run on the IGN coil igniter? Pickup coils? Thank you for all the help! 

Do you have the factory Kawasaki manual?  If not, it's available for free download from this site in the Articles tab here.

The pickup coils are reliable, more so than the ignitor.  The wiring is most suspect of all though.  

Good luck with your project.

Voltage is a little low. What does your meter read on the battery posts?It should read close to 13.2v.
With the meter still connected to the battery posts (not wires) turn the key on and note the voltage. There should be little change.
Next press the starter button and note the voltage again. If it drops to 10 or lower, the battery is likely bad.

Grab your meter
meter on DC V
everything connected

key on/ignition on

black probe on negative battery post(post is the metal part of the battery not the cable)
red probe on positive battery post
note voltage

move your red probe to each of the wires in the pink box
measure the ignitor side of the connector.
you'll have to backprobe the connector as it must remain connected.

Black/yellow is ground so your voltage should be as close to 0.0V as possible.
If it's higher than 0.5V then you have too much resistance on that ground connection.

The yellow/red should be close to battery voltage that you measured at the beginning.

The green and black should fluctuate as you press the starter button.
the voltage will fluctuate between 0.0v and 12V

Alright gents, I’ve done exactly as you’ve asked and got some weird answers.
12.25V at battery terminals
.05v from ground post to black/yellow
11.65 ground to red
11.61 ground to green at all times 
11.09v ground to black at all times

there is fluctuation however they never drop below 11V when cranking. They never return to zero like you suggested they would. I’ve probed from both sides of the connection with the same results. 

The voltages seem fine.

ok, we'll check your ignition pickups next.
It appears your ignitor is not sending a ground signal to the coils.

When your coils get a ground signal on the green or black wires they charge up(you'll see 0.0V on the green or black).
When the ground signal is cut on the green or black wires the coils fire the spark plugs (you'll see 12V-11V on the green or black).

Let's check the pickups
the connector is in the green circle
meter on AC V
key on/ignition on
backprobe the connector on the ignitor side
leave the connector attached

red probe on the yellow wire
black probe on the red wire
push the starter button
you should see a low ac voltage as the engine turns

red probe on the blue wire
black probe on the black wire
push the start button
note the ac voltage

Turn off the bike

Lou may jump in as he knows this ignitor circuit better than most of us.

just out of curiousity---have you tried using starter fluid? It could be a fuel issue.

wrote:

Alright gents, I’ve done exactly as you’ve asked and got some weird answers.
12.25V at battery terminals
.05v from ground post to black/yellow
11.65 ground to red
11.61 ground to green at all times 
11.09v ground to black at all times

there is fluctuation however they never drop below 11V when cranking. They never return to zero like you suggested they would. I’ve probed from both sides of the connection with the same results. 

As F64 said, your voltages seem ok.  It would be nice if the battery was a bit higher, but if it's cranking quickly enough, the battery is fine.

The voltages on the green wire and black wire (those wires go to the coils), will generally be near 12v when the engine is not turning.  Then, while cranking, they will just briefly pulse to near zero.  It may be too fast to get a good reading on the meter depending on how fast your meter can react.

It should be mentioned, though, that after the brief 0v pulse, there is a very brief spike of 300v to 600v on the green wire and black wire when everything is wired normally and working.  If your meter is not rated for 1000v, there is potential to damage the meter.  To do the test safely, you should make sure all four plug wires are shorted to the engine, or ground, or any other piece of metal.  This will short out the spike and protect the meter.  Obviously, you won't see a spark this way.  So to see spark you need to do a different test.  Basically the same test, but instead of shorting the plug wires, put a plug in each plug wire and lay the plugs so their bodies touch a common piece of metal.

Once again I come back with interesting results. I followed the test for the pickup coil AC voltage check and got nothing, no reading at all. I’ll add pictures to show what my meter was set on and the wires I had backprobed. Not too familiar with AC voltage on a multimeter but you guys should be able to make sure I am set in the right direction. 

your meter appears to be set correctly for ac voltage.
You may also be having trouble trying to get the probes to touch the metal terminals.
Since we're not doing voltage drop testing on this you can disconnect the pickup connector.
You can then measure the terminals more directly.
Try the pickup measurement again.

Then measure the resistance of the same wire combos.


open up the cover that houses the pickups.
post a photo of the ignition pickups.

 

Pictures as requested. And I unplugged the connector and made sure I had connections when I turned it over and still nothing. Tried an ohm test with the same wires, nothing. 

Thanks for the nice picts.
It appears your pickups are faulty.
It could be a break somewhere along the wires to the pick up.

I'm going to suggest something.
See if you can measure resistance of the wires poking out the bottom of the pickups within the green circles.
Unplug the pickup connector you were measuring from before

Gotcha, 

multimeter Set to 2000ohms
5ohms from yellow to yellow
2 ohms from red to red
2ohms black to black
2 ohms blue to blue