JD LT 160 stops when mowing

[Ed 22]

Hello, I have a John Deere LT 160, 10+ yo mower, and since some weeks the motor often stops, only when I'm mowing. It happens even if there is no grass to cut, so I suspect it's not a problem of power.

If I manage to quickly disengage the blades (driven by belt transmission) with the yellow lever on the right of the wheel, it fires back to life. It just seems like the RPM quickly fall to 0 in some seconds, but...

If I just drive around without mowing it works fine, and doesn't stop for no apparent reason, so apparently it's not a spark plug problem. Sometimes I can mowe for some long minutes, but now it happens more frequently. I try to stop for a long pause, sometimes I can work again for some time, or just drive a bit without engaging the mower, but it's quite erratic.

Any idea of what is wrong ?

 

[pohorsky]

Might be something to do with the PTO lever (yellow lever). If you hold down the button for reverse mowing, does it still shut off?

 

[GreenCamo]

While your PTO (mower drive) is started/stopped with a manual lever, it operates an electric PTO clutch which, without enough electrical power will cause the engine to die. I would first check your battery with the engine off, engine running and VERY CAREFULLY when the PTO is engaged.

 

[Ed 22]

Might be something to do with the PTO lever (yellow lever). If you hold down the button for reverse mowing, does it still shut off?

The yellow button on the left doesn't have any effect when the problem happens.

While your PTO (mower drive) is started/stopped with a manual lever, it operates an electric PTO clutch which, without enough electrical power will cause the engine to die. I would first check your battery with the engine off, engine running and VERY CAREFULLY when the PTO is engaged.

I will try to find a way to measure voltage on the battery while the PTO is engaged. But voltage should be the same in any of these 3 cases ?

I have now found a very thin white electric cable that is cut, but I doubt it's something new, as I had some animal eat the spark plug cable 2 winters ago, (I had to change the whole ignition coil module on the other side of the motor).

 

[Gordon Gould]

Did you ever get this figured out ?? Just curious because I have that same mower which I bought in 2002.

gg

 

[Ed 22]

Did you ever get this figured out ?? Just curious because I have that same mower which I bought in 2002.

gg

No. I hope I have some time next days, to repair the white cable, maybe connect the voltmeter to the battery as suggested by Greencamo and see if I spot some change (although I'm not sure what to do in this case).

I also wonder if this could be some misalignment of the mower, but I don't hear anything suspect, which would sound like a friction. Just the RPM falling and motor stopping in 2-3 seconds.

I also had to use the left button while engaging the PTO clutch when I started using the mower this spring, else it would stop the motor. This was not necessary before, but now that's back to normal, I can start the mower without this button.

Of course if someone has another idea.

 

[Gordon Gould]

Sounds like it thinks it is in reverse some times. I don't know where that sensor is but I would start there if it were me. Could be on the reverse pedal/linkage or maybe a hydraulic switch on the transmission but that sounds to expensive.
When you find it let us know - thanks

gg

 

[jimmysisson]

With the mower off it works fine? Have you checked for bad spindle bearings or idler on the deck?
Jim

 

[Ed 22]

Today I connected and taped the white wire, and managed to use the mower for more than half an hour, without any problem. I really hope this was the problem, but I don't understand how a cut electric wire (no connection left) could cause this kind of erratic breakdown, so I'm not convinced it's really fixed yet (as I said it's not systematic).

Sounds like it thinks it is in reverse some times. I don't know where that sensor is but I would start there if it were me. Could be on the reverse pedal/linkage or maybe a hydraulic switch on the transmission but that sounds to expensive.
When you find it let us know - thanks

gg

As you said, it "sounds" like when I reverse while mowing without pushing the button, and cause the motor to stop.

With the mower off it works fine? Have you checked for bad spindle bearings or idler on the deck?
Jim

Yes, it works fine. Can't check that, I think I'm not equiped to remove and take apart the deck !


PS English is not my first language, sorry for any mistakes.

 

[Gary Fowler]

This sounds like it may be the operator presence switch in the seat. IF it shorts out (like it thinks you got up from the seat) with the mower running, it is going to shut off the engine. Turning off the mower would possibly allow the engine to keep running. I would check that or replace it.
Some mowers allow you to get off the mower if the PTO is not engaged without engaging a brake, others require a brake to be set before you can get off. It may actually be both of those switches or one of them that is acting up assuming you have to set the brake AND turn off the mower to dismount.