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Hi,
I have a Toro Timemaster Lawn Mower, and it won’t turn off.
I already tested all 3 contact points and there is continuity (when switch is enabled). I also tested switch and it is working. I changed the switch and ground cables to new ones, just in case, but it still doesn’t work.
I already replaced ignition coil, and it still doesn’t shut off. It turns on the first time, issue is when turned off. I tried an Amazon version, and also an original Briggs and Stratton ignition coil, same case, it just doesn’t turn off.
I already tried grounding the ignition coil while running, to the same lawn mower, and also tried connecting a cable directly to a battery’s ground with no success. Problem is the spark plug keeps getting voltage, even when I try to manually ground it. There is no physical break on Timemaster, so I don’t know what else to do.
PLEASE HELP!!!

Start by grabbing your owners manual and look at the wiring diagram near the end
If you have lost yours they are a free download from Toro as is the service manual & parts manual

Usually no shut off is because the kill wire has fallen off the magneto or has been cut / chewed through
So pull off the blower housing and check the white wire that goes to the coil
on = open circuit , so no voltage between it and either terminal on your battery
Off = Ground so no voltage to the ground terminal and battery voltage to the positive terminal
People seem to have a problem wrapping their heads around ground switching

If the wire does go to ground then the coil is faulty and needs replacing .
If the wire is intact but does not go from ground to open to ground when the key goes from off to on to off then the next place to go is the ignition relay
The relay shifts ground from the coil to the starter relay and PTO and is energised every second the engine is running
They can stick & fail
The quick test is to pull the blade switch up then try to crank the engine
If the engine cranks then the relay or relay housing has failed .

Most of the time it's because you have to hold down the shutoff switch until the mower stops. If you let go too soon the contact breaks because it is a momentary switch and the engine keeps running. If that is not it I don't know....

bertsmobile1 said:

Start by grabbing your owners manual and look at the wiring diagram near the end
If you have lost yours they are a free download from Toro as is the service manual & parts manual

Usually no shut off is because the kill wire has fallen off the magneto or has been cut / chewed through
So pull off the blower housing and check the white wire that goes to the coil
on = open circuit , so no voltage between it and either terminal on your battery
Off = Ground so no voltage to the ground terminal and battery voltage to the positive terminal
People seem to have a problem wrapping their heads around ground switching

If the wire does go to ground then the coil is faulty and needs replacing .
If the wire is intact but does not go from ground to open to ground when the key goes from off to on to off then the next place to go is the ignition relay
The relay shifts ground from the coil to the starter relay and PTO and is energised every second the engine is running
They can stick & fail
The quick test is to pull the blade switch up then try to crank the engine
If the engine cranks then the relay or relay housing has failed .

Click to expand...

Hey! Thanks for your comments. I checked the switch, the cable and also de ignition coil, but everything was OK. At the end I was able to find the issue, the ground was close to the carburetor, and after cleaning the carb, I added a gasket and looks like it prevented the whole area to be considered ground.
Since there was no “connection” between the whole ignition area and the groin, it was not turning off.
After I grounded it to the chassis close to the ignition coil, it was able to turn off with no issues.

slinger2 said:

Most of the time it's because you have to hold down the shutoff switch until the mower stops. If you let go too soon the contact breaks because it is a momentary switch and the engine keeps running. If that is not it I don't know....

Click to expand...

Hey there! I did try to hold it for several seconds and it was not turning off. The issue was the original ground was interrupted by a gasket I added after cleaning the carburetor. It looks like it was not allowing the whole circuit to “close”.
After grabbing other area close to the ignition coil as ground, I was able to kill the machine with the switch with no issues.