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1980 z1 classic fouling plugs 04 Sep 2023 19:52 #889035

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NGK BR8ES - I dont believe they make the non resistor version anymore. NGK dont seem to list them here.  I have not found them in 2 years

7.8 volt at the coils when running.  -  remember that when the engine is running the coils are energised then the power is switched off by the points opening or the ele tronic ignition and the field colapses and spark is generated so the voltage would not be constant on a running coil. At least thats my understanding but one of our electrical gurus can confirm if coil voltage on a running motor is of use.

11.84 volts at the kill switch - kill switches can and do get corroded but so also  do ignition switches. Some ignition switches can be opened and serviced. Some cant, like the ignition swirch on my 750 which I had to replace several years ago. Cant remember what the voltage drop was. More than 1 volt anyway.

good luck
1980 kz750E1, Delkevic exhaust

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1980 z1 classic fouling plugs 04 Sep 2023 21:00 #889037

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You mentioned this at the very beginning.

Your computer may be adding more fuel than the engine needs.
Is it possible to create an air leak after the air flow meter?

This will verify you have a fueling problem.

Have you modified any part of the intake system?
81-KZ440-D2.
Louis Dudzik's GM HEI ignitor conversion installed 2015 s3.amazonaws.com/gpzweb/Ignition/GPZgmHEImod.html
Motogadget m-unit blue installed 2017.
LIC, NY

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1980 z1 classic fouling plugs 04 Sep 2023 23:46 #889041

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That 10.8 v to the coils coupled with cap AND plug resistors is the cause of the black plugs. An extremely weak spark I'm surprised it even ran.
Bin the resistor plugs fit non resistor denso W24ES-U for ngk8 heat range equivalent or denso W22ES-U for ngk7 heat range equivalent. Correct the low voltage to the coils by either cleaning all the contacts and switches in the ignition circuit paying particular attentention to the kill switch or fit the wired George relay mod and you should be good to go. 
 

Z1000J2 somewhat modified!

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1980 z1 classic fouling plugs 05 Sep 2023 00:09 #889042

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I measured with just the key on since the injectors are still out.  Both coils read 10.8v.  Are you asking me to measure it once the bike is idling?  I will do that once I put the injectors back in.
What was the battery voltage when you had 10.8v at the coils (any more than 0.5v difference signifies a problem) maybe time for a by-pass relay mod 

the plot thickens…. 10.9v key on ,  battery at 12.12v.  Start the bike and the voltage goes to 7.8volts on both coils when measuring the green or black(depending on coil)  to ground. Crazy drop there and the bike can barely idle without me giving some throttle. 


 
You are measuring incorrectly which is why you are getting that ultra low reading, meter black lead should be on battery ground and the red lead should be on the "input" side of the coils. The black and green are the switched side so will only show voltage during the ignition "firing" period when the ground is broken.
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1980 z1 classic fouling plugs 05 Sep 2023 02:07 #889046

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You mentioned this at the very beginning.

Your computer may be adding more fuel than the engine needs.
Is it possible to create an air leak after the air flow meter?

This will verify you have a fueling problem.

Have you modified any part of the intake system?


The intake system appears to all be stock. I have not modified anything there since the FI system was reinstalled. 

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1980 z1 classic fouling plugs 05 Sep 2023 02:19 #889047

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So I need to measure the red wire that is feeding the ballast resistor, that also seems to power the IC igniter?  I had put my leads on the connections soldered to the primary inputs on the coil itself, well at least one of them to ground.  I pulled the fuse for the headlamp out so I don’t keep lowering the battery voltage while I am measuring system voltages but this will give me a false reading as the headlamp has its own draw. That is why I now am seeing 11.8v vs the 10.8v I started with when the key is on.  The primary white wire fuse holder needed cleaning up, also found that the connection there was hot at one point as the plastic clip/fuse holders are both melted.  

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1980 z1 classic fouling plugs 05 Sep 2023 02:22 #889048

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I like this relay idea.  For a test only I was wondering if I connected my dc power supply to the coil feed wires at 12v what would the bike do?  I don’t want to fry anything….

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1980 z1 classic fouling plugs 05 Sep 2023 02:22 #889049

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So I need to measure the red wire that is feeding the ballast resistor, that also seems to power the IC igniter?  I had put my leads on the connections soldered to the primary inputs on the coil itself, well at least one of them to ground.  I pulled the fuse for the headlamp out so I don’t keep lowering the battery voltage while I am measuring system voltages but this will give me a false reading as the headlamp has its own draw. That is why I now am seeing 11.8v vs the 10.8v I started with when the key is on.  The primary white wire fuse holder needed cleaning up, also found that the connection there was hot at one point as the plastic clip/fuse holders are both melted.  
If you connect the voltmeter - red lead to battery positive and black lead to the red wire going into the ballast resistor this will measure the difference between the 2 points (max 0.5v) then the result won't be effected by falling battery voltage

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1980 z1 classic fouling plugs 05 Sep 2023 02:26 #889050

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I like this relay idea.  For a test only I was wondering if I connected my dc power supply to the coil feed wires at 12v what would the bike do?  I don’t want to fry anything….
For a test you can bridge from battery positive to ballast resistor input (not direct to the coils as you will double the current flow through them and the igniter) MAKE SURE YOU HAVE A 10a FUSE IN YOUR BRIDGE LINK

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1980 z1 classic fouling plugs 05 Sep 2023 14:55 #889082

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So I need to measure the red wire that is feeding the ballast resistor, that also seems to power the IC igniter?  I had put my leads on the connections soldered to the primary inputs on the coil itself, well at least one of them to ground.  I pulled the fuse for the headlamp out so I don’t keep lowering the battery voltage while I am measuring system voltages but this will give me a false reading as the headlamp has its own draw. That is why I now am seeing 11.8v vs the 10.8v I started with when the key is on.  The primary white wire fuse holder needed cleaning up, also found that the connection there was hot at one point as the plastic clip/fuse holders are both melted.  
If you connect the voltmeter - red lead to battery positive and black lead to the red wire going into the ballast resistor this will measure the difference between the 2 points (max 0.5v) then the result won't be effected by falling battery voltage


With the key off the 2 readings are 12.75 +battery to - ground, 12.42 +battery - to red wire feeding ballast resistor.  Key on +battery to - ground 12.33,  +battery - to red wire 11.97.  Neither of these readings are greater than 0.5v drop. 

 
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1980 z1 classic fouling plugs 05 Sep 2023 18:11 #889092

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Update for this evening.  Made a jumper wire from battery direct to red input wire at ballast with a 10amp mini fuse.  Got 12v there, left all other connections intact.  Started bike , coughed choked and still having wet and fouled plugs. Disconnected that and plugged the stock wiring back in.  Opened the maf and just started measuring voltages on each lead at the circuit board with the key on.  Everything seems ok.  Varying voltage as I measure along the potentiometer.  I did notice that I have 6.8v on the housing of the maf when measuring to ground , the circuit board is mounted to metal and it is screwed to the aluminum board so I was perplexed at why there is voltage there even when the key is off. Pulled all 4 plugs and they were wet.  By the way I do not have the injectors bolted in yet, they are just pushed in to the holes sealed by the orings at this point.   Dug in my old spark plug box and found three b8es and one b7es plug,  cleaned them up and checked in the spark plug tester, had spark.  Installed these and started the bike again, turned up the idle so I didn’t need to hold the grip.  Smoking like crazy out of both pipes. Oil was dripping from the #3 cylinder pipe seam too.  Think the excess unused gas is washing the walls of the cylinders off.  Shut it off and let the smoke dissipate out of my garage…. 

I went back to the potentiometer as something didn’t sit right with me on that.  Then I unplugged the connector to the maf and it still had 6.8 v with nothing plugged in to it.  So I pulled the maf sensor out and looked for a chaffed wire or something that would be shorting against it.  Did not see anything,  then I noticed a wet spot on top of the battery.  Put my positive lead on the wet spot and got 6.8v.  The top of the battery is leaking and conducting through the maf sensor housing , screwing up the voltage to the computer and with higher voltage means more gas as it thinks it is at WOT… wiped it off both parts and put a piece or plastic over the crack for now.  Started the bike again and it smoked for a bit but it wasn’t choking or sputtering, let it idle and gave it a few good cracks.  Sounded good.  Let it idle more and the smoking went away.   Now I need to reassemble everything and test it.  Also time for another battery!  Hope this is it.  Makes sense to me.  It was too much fuel all along. 

 Tried to attach some pics of my gas circulating system set up and the findings today.



 

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1980 z1 classic fouling plugs 06 Sep 2023 00:07 #889098

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This seems quite bizarre, still a "win" is a "win"   I would suggest a piece of rubber mat between the MAF and the new battery as it appears the damage to the battery has been caused by the MAF rubbing ?
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