Outdoor Power Equipment (Lawn Mowers, Snow Blowers, Chain Saws and more) Discussions

The cable connecting the safety bar to the engine on our basic push mower seized, and the lawnmower would stay on, and the only way to turn it off would be to pull the spark plug cable off (very dangerous).

I replaced the cable tonight and everything works, except when testing the lawnmower still wont shut off. The new cable allows the leaver to move just as much as the old one did, so I know its making full contact.

I notice the engine also makes a slightly different sound when the safety bar is push down and when it is up. The engine seems to run a slight bit faster with the bar engaged, then when I let go it slows down slightly but nothing very obvious.

What area should I look at first?

thanks.

Subs.
It would really help if you gave the model numbers of the mower and the engine.
Depending on the type of engine, the brake switch could be bad....
or the wire from the switch too the module could have a problem...
or brake shoe could be completely worn down from running on when it should have been shutting off and is going past the shut off point....
Briggs generally uses a brake on the outside of the flywheel...while you have too remove the flywheel on a tecumseh.
Knowing the model numbers cuts the guessing by 50%.

Good call

Its a Tecumseh 3.5 HP

TVS90 is the model of the engine.

The last mower I looked at that had one of these had the cable connected to a rather cheep looking switch. When you released the bar the switch would short out the ignition system and the mower would stop. It worked much like the "ignition" key on a snowblower.

The first thing that I would check is to see if the cable is actuating the switch properly. If the cable is too long then the bar will still move "correctly" but the switch won't actually be engaged. If it is actuating the switch then check to see if the switch is working properly.

Take a look at the brake arm coming out from the engine. Note if it is moving when you let the safety bar go. The engine stop brake is spring loaded. If it is not moving like it should, you can lubricate it. If that doesn't work, you will have to replace it. Your kill switch is part of the brake assembly. Good luck, Carlw

thanks to all those that responded.

I noticed the switch was a little coroded inside, so I put some MG Chemicals Nu-Trol control cleaner on the switch and moved it back and forth. Everything seems to be running fine now, and the mower operates 100%.

Things are looking up for the tecumseh lol