View Full Version : Grasshopper 725k2 - PTO will not engage

07-17-2007, 04:09 PM
I have a grasshopper 725k2 and all was working fine until I ran out of gas and the mower stopped with the PTO switch engage. I disengage the switch and filled the mower with gas but now the blades will not engage. I do not hear the switch click if I pull the switch to engage. The mower will still start up. Any suggestion?

07-17-2007, 04:12 PM
looks like it's time to dig up a schematic and a multimeter! :cry:

07-17-2007, 04:27 PM
Yeh, thats what I was afraid of. Just thought it may have been something simple since it worked right before I ran out of gas.

07-17-2007, 05:08 PM
it still could be something simple.
if you have the schematic and a multimeter, it shouldn't be too hard to find.
it's probably a relay or a fuse somewhere.
good luck!

07-17-2007, 05:52 PM
berfore you do anything YOU MUST DO THIS let the mower run and then put a 12 volt battery charger on it and then with the mower going and the charger going try the pto if it works then let me know ill go into more detail good luck

Envy Lawn Service
07-18-2007, 12:50 AM
Well, I was going to start my own thread, but considering this one, I think I'll try piggy-backing here first.

I had sorta the same thing happen to me today...

I forget for sure, but I think what happened was that I shut the PTO off. Then I leaned over to get something off the top of the deck, and the kill switch under my seat cut in. I got back on the seat before it died, but then the pto did the same as described here.

I cut the mower off and tried to check the connections.
Fired it back up and it still didn't work.
So I tucked my tail and headed for the trailer.

This was a big site so it was a good drive... just out of stubborness, I pulled it one last time before hitting the gate. It worked and worked flawlessly the rest of the day.

I'm very puzzled by this.

07-18-2007, 12:38 PM
briandennis1470, I was thinking the same thing yesterday about the voltage because the mower seemed sluggish to start. I purchased a new battery yesterday and now the mower starts up very quickly. The PTO still will not engage. Envy Lawn Service, once I find out what is causing the problem, I'll post it here.

Envy Lawn Service
07-19-2007, 02:16 AM

Mine is still working as it was... but I'm still scratching my head over the momentary failure.

The only thing I have been able to dream up is an intermitant connection... Otherwise, I was thinking that I did cycle the deck off and on a BUNCH of times on that account. It's a big sparse dust pit now. Maybe it got hot and quit on me until it cooled down? I don't have a clue.

07-20-2007, 09:51 PM
Turned out to be the switch. Replaced the switch this evening and all works fine.

03-22-2008, 11:37 PM
Well it happened again. After I replaced the PTO switch last year, it worked for the rest of the year. Today was my first time using my mower this season and it worked for half the day. Then while cutting the blades stopped but the engine remained running. Cut off the engine and tried to start her up again and the battery was low. Jumped off the mower but now when II pull the pto switch, the engine cuts off. Picasso Services, leave the 12 v connection and the pto works, what do you think the problem is? I will try this in the morning.

03-22-2008, 11:39 PM
Forgot 1 thing. The first time this happened today and I jumped off the mower, the pro switch worked. The second time it didn't and the engine cut off when engaged.

03-23-2008, 02:21 AM
Bad battery ? It does not have enough juice to engage.

Stathem Lawncare
03-23-2008, 01:32 PM
Check your seat switch. Make a jumper wire and pull the plug and put your jumper wire in the plug. Had the same thing happen last year.

04-13-2008, 06:35 PM
I replaced the battery and all was fine. It lasted all day. 2 weeks later, was cutting grass and stopped to fill up and when I tried to start up again, it wouldn't start. I jumped it off and started cutting again. While cutting, the pto disengage and the mower started to cut off still I manually disengaged the blades. I made it back to the house and turned off the mower. Tried to start it again and this time not even a click. I could jump start it again but it seem like the battery is not being charged. Could it be the alternator or maybe a voltage regulator? Any thoughts?

04-13-2008, 06:40 PM
we always carried pto switchs with us, seems pto switch was usually the problem.

05-22-2008, 03:42 PM
Well to let you know, the problem was not the battery but rather the stator. It is a bugar-bear to replace but that fixed the problem. Now I need to find out what is wearing down my belts. I have to replace the belts every 16 - 24 hrs of use. Any suggestions?

06-18-2008, 01:56 AM
I am having a very similar problem with my GH 727K2. I was having to jump it to get it to start but the PTO would engage and it would mow just fine. Then I started having problems with the PTO choking and stalling the engine. When I would try to start it up again (jumping it) I couldn't get the PTO to engage at all. I noticed the voltage was pretty low so I suspected the battery.
So I replaced the battery and it started right up and worked great for a day. Today it started easily and I mowed for a little over an hour until I got into some tall grass and it choked a little and the engine stalled. I had to jump it to get it started and the PTO will not engage again.
I'm suspecting the alternator but don't know for sure. I'm not much of a mechanic so I don't know how to verify this.

05-19-2012, 03:42 PM
This happened to me today. Mower engaged and ran fine yesterday, but today, the PTO will not engage. The mover runs fine and I am getting 13.6 volts at to the switch. I have 3 yellow wires and 2 brown - I am getting the 13.6 voltws to the outside brown wire. The yellow wires I assume are for the safety (seat, arms,) - how can you check the switch or how is the best way to by pass.

05-19-2012, 05:14 PM
I did trouble shoot the PTO switch and found it not to be working (I had to find a set of schematics first). The yellow wires are for the safety components while the two brown are for the PTO. I confirmed one brown was carrying 13.7 volts and there was no continuity in the switch between the two brown wires. I bypassed the switch my putting an old toggle switch I had (between the two brown wires) - the PTO works fine. I have ordered a new switch.