ZG124E Runs on after key is turned off

gb1969

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I am working on a ZG124E with a Briggs and Stratten 44M777 V-twin engine. The engine runs for approximately 5-10 seconds after the key switch is turned to the off position. I don't know if this is normal procedure, I don't think it is. I have checked continuity from main harness connector to key switch and from key switch to ground and from ground through the key switch. All is good. I have tested the kill wire in the engine harness and it tested ok. I even replaced the kill wire with a new one and it still runs on after the key is turned off. It finally shuts off when it runs out of gas due to the fuel solenoid in the carb has closed the jet opening. Has anyone come across this issue or is it an issue? Any feed back is much appreciated.
 

bertsmobile1

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Carbon build up inside the engine or wrong plugs or running too lean

Double check the coils by fitting an in line test lamp which should not flash after the key is turned off .
 

Bertrrr

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Check your Kill solenoid under the Carb, this is what helps it shut off without backfiring.
 

gb1969

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Sorry I have not responded back. I have checked the coils with an inline spark tester and they are not shutting down. I replaced the engine harness thinking I had bad diodes in the kill wire, even after testing them and the results showed the diodes were good. I have also replaced the key switch. The fuel solenoid is working properly and is the only reason it shuts off, it finally runs out of fuel. I can kill the coil output by bypassing the diodes and just going straight to ground with a pair of wires I attached to the terminal on each coil, keeping them separated so no backfeed is possible. It will shut down instantly when I do this. I am at my wits end.
Thank you for your responses.
 

bertsmobile1

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The ground connection to the key switch is bad
when youshut down the key switch connected the M ( magneto wire ) to the G (ground wire )
So as the switch is new then either it is wrong or there is no ground on the black ground wire
If it uses an ignition relay then the relay could be bad but generally an ignition relay defaults to the off position .
 

gb1969

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I have checked for ground at the key switch terminal, it is actually the first thing I checked. The key switch is OEM from Kubota. I have checked and cleaned all my ground connections, at least three times. I have not found a relay in the system, but I am considering installing one.
 

bertsmobile1

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On the key switch there should be a wire that eventually goes to the magneto kill wire
To turn the engine off the key connects M to G
So if you have ground on the G wire and the key is connected the M & G together then somewhere from the key plug to the magneto that wire is broken .
Now a lot of wiring passes this wire through the PTO switch so you could have a bad switch or a wire broken at the crimp on a terminal
FWIW
When I have a problem like yours I use a pile of short jumpers with a male on both ends to make the contacts at each plug
I also have a bag of longer ones I use to bypass the loom between individual plugs ( switches )
It is a long process and the last one you check is always the broken one
And remember you are checking for ground from the key switch, through the PTO switch then on to the parking brake switch then to the magneto
 

dana a

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I had that problem with my Khroler engine. It had an oil leak and puked oil all over it and then dust and grass collected on the cooling fins and it would over heat. I took the engine out and fixed the leak and cleaned the engine and then it would shut down when the key was turned off. So my guess is it is overheated and is running like a diesel due to being so hot.
 

StarTech

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