Lawn Boy won't shut off

[viperv10]

I have a duraforce easy stride mower model10550 that keeps running when I let go of the bail brake handle.
I can't figure it out. I looked at a duraforce repair manual and it shows an open circuit to run. Closed circuit to shut off.
When I let go of the handle the spring pulls back and make contact and it should shut off but it doesn't.
I took sand paper and rubbed it on both contact points and also checked the continuity on the wire from the shut off switch to the coil and it was good.
I have 3 other duraforces and they all work the same way. I can't see any difference between any of them. It won't even kill when I throw the throttle lever up to choke.
Most small engines will die when you throw the choke on, but this one wants to keep chugging on. Does anyone know what might be going on and how to remedy this?
Thanks.
Jerry

 

[FuzzyDriver]

At the coil, disconnect the wire that runs to the contact point. Connect an alligator-to-alligator jumper from that coil terminal to one of the fins on the cylinder. If the mower will still run then you have an open curcuit INSIDE the coil assembly, and you will need a new coil to fix the problem. If the mower will now not run, leave the alligator on the fin, reattach the wire to the coil terminal, and move the other alligator to the end of the wire. You probably already understand where I'm going with this - moving a definite short one step at a time until it stops running. The switch terminal is next, with the wire on the terminal. At some point you will get to the point where it keeps running. Good luck!.

 

[viperv10]

I went out today and started the mower and let it run for a few minutes and let go of the bail and it shut right off. So I restarted it about three more times and it stopped right away
every time. It was so weird, just like it was a different mower. This sure beats having to pull the spark plug wire off every time. That thing will bite you a good one if you're not careful.
I like lawn boys but they can be very finicky. I have sold a few and just about everyone who buys one calls me back up sooner or later and says they can't get them started or have some kind of problem.
Thank you for your reply.
Regards
Jerry

 

[FuzzyDriver]

Fixed itself....I hate those problems.

 

[viperv10]

Well, so much for easy fixes. I was ready to give this mower back to its owner, so I started it to make sure it was running right. I mowed 2 strips across my yard and let go of the brake bail handle
and the thing kept right on running. I thought not this again. The only other thing I could think of was to swap out the coil and see if that helped. Luckily I had a new dura force coil I had just gotten on
Ebay from graveyardmowerz.com. Well it fired right up and shut off like it was supposed to. I tried it 6 or 7 times and it shut off every time. I'm guessing it was something inside the coil misbehaving.
Regards,
Jerry

 

[Born2Mow]

The problem is that your mower is "possessed". It's no longer a Lawn Boy, but instead a "Lawn Zombie".

You don't need a mechanic, what you need is an exorcist !!