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Hello, Replaced both coils on a John Deere D140 with a twin Briggs 407777-0170-G5. It cured the dead cylinder, but now has a shut down problem. When you turn the key to off it takes a few seconds to stop running. I believe the fuel solenoid is turning off the engine, not the spark being shorted. I replaced the coils with Stens 440-445. The kill wire has 2 diodes in-line. I have ohms one way and not the other. Voltage to the coils?

Thank you
Eric

A single diode tests as you describe, not sure on the doubles. And I wonder about diodes in a kill circuit. Something odd going on here.

Easy check is to fit a red in line spark tester and watch it as the engine comes to a stop.
If it is flashing after you turn the engine off then your suspicions are confirmed .
Do both cylinders and get back
The kill wire is a ground wire and he diode is to prevent one coil sending a false signal to the other one.

bertsmobile1 said:

The kill wire is a ground wire and he diode is to prevent one coil sending a false signal to the other one.

Click to expand...

Aha! As I've said before, learn something every day on here.

Note some JD mowers dont the kill circuit connected and depends on the fuel solenoid for shut down.

StarTech said:

View attachment 54103
Note some JD mowers dont the kill circuit connected and depends on the fuel solenoid for shut down.

Click to expand...

Which ones ?

The L series diagrams show the diodes in the coil circuits and separate line to the solenoids as above.

bertsmobile1 said:

Easy check is to fit a red in line spark tester and watch it as the engine comes to a stop.
If it is flashing after you turn the engine off then your suspicions are confirmed .
Do both cylinders and get back
The kill wire is a ground wire and he diode is to prevent one coil sending a false signal to the other one.

Click to expand...

Sorry I did not reply earlier. Found the notification in my spam folder.
With spark tester, both cylinders spark until rotation stops. Also with the key on, I have battery voltage on the kill wire.

StarTech said:

View attachment 54103
Note some JD mowers dont the kill circuit connected and depends on the fuel solenoid for shut down.

Click to expand...

This wire diagram is correct for my mower D140. The question I have is, Why power going to the coils? 13 plus while engine running. Did the original coils need power?

B&S engine coils do not need nor want battery power to them. That is a death Nell for B&S coils.
Walt Conner

Solution. Stens 440-445 do not work on Briggs 407777-0170-G5 Even though the engine starts and runs well the key will not short them out. Purchased OEM Briggs 592846 and everything is back to normal. In most cases Aftermarket work just fine, but not this time.

Yes, you likely need new ones now. Leave the wires off until you figure it out.
The kill wire goes to ground to shut the engine down, no voltage should be there.
Have you recently replaced the keyswitch? Repaired any wires? Etc.??