Anybody A Zero Turn Mechanic
buddyb
Member Posts: 5,244 ✭✭✭✭
I am working on a Husqvarna PZ 5426 zero turn.This is about a $11,000 commercial machine that professional lawn care companies use.It is powered by a 26 HP Kawasaki.The guy who owns it took it to the local dealer and it was there for 6 weeks and they never started working on it.The owners ask if I would pick it up and put a starter on it, change the oil and sharpen the blades.I charged the battery, started it up and cut my back yard.When I pulled it in the shop,it would not cut off with the key.After much checking with the multimeter I determined one of the coils was bad.I replaced both coils and it started up and turn off with the key like it should.It runs fine but when you take off the hand brake,move the control levers or engage the blades the safeties are killing the engine. I by passed the lever and hand brake safety and it will start and move just fine but when the blades are engaged it still kills the engine.The seat safety checked out good so I am trying to figure out what to do next. If Perry Shooter was still with us he could probably tell what the problem was pretty quick.Any suggestions
Comments
The hand levers both arms... to control speed may not be set all the way open..or one of those safety devices need replaced.
I have the control levers and parking brake safeties held open with zip ties.
Did you check all switches with multimeter to see if they were good ..even though tied back... I know the Kubota quit and I had the seat safety switch taped .. it went bad.
Some safety switches are TWO way switches. Some have to be closed for one motion BUT open for another motion. Simply taping them shut will cause issues, IF they are 2 way switches.
All the safeties were good with the multimeter. The PTO and ignition switch are new and tested good.I dont know where the safety for the for the PTO/blade engagement is located is that is the one I am having problems with.The safeties I have by passed are for troubleshooting and will be put back when the problem is found.
On my Gravely, the clutch has to slip a little to get the blades turning. If the clutch is worn and is metal to metal, would that stall the engine?
Pretty sure its not a clutch problem. It only got 334 hours and never been abused.
worked in electronics for 45 years, very hard to troubleshoot a problem like that without a schematic. should b able to find one on line. also on most all lawnmowers the ign. switch when turned to off shorts the coils to gnd thus stopping the spark. when turned to on it removes the gnd and enables the coils to produce spark. this gnd goes thru almost every safety switch on the mower, need a schematic.
IF you "bypassed" the brake safety switch, then it most likely will not move. For example.....brake has to be "set"(switch closed) to get out of the seat, BUT that SAME switch must be open(and seat switch closed) for the mower to drive.
You have to KNOW if the switches are 2 way or not before you start bypassing them!
One of those safeties that you bypassed is causing your issues! PTO probably thinks the brake is set, and/or NOT getting the correct voltage from one of those switches. If any of the switches have more than 2 wires, then they are most likely TWO way switches.
One of the switches is probably faulty, but simply "bypassing" 2 way switches causes ghost problems.
My zero turn will kill the engine if the parking brake is on and you try to start the blades. That tossed me a curve this spring. I guess they do that so you don't burn out the transmissions.
They do that so you cannot get off the mower with the blades running. Brake on, then the seat switch is inactive. Mine will shut off if you take the drive arms out of neutral with the brake on. These switches are NOT simple on/off switches.
The mower would not move before I by passed the brake and lever switches.It now starts,drives fine but dies when the PTO is engaged.The safeties I by passed were plunger switches all of which tested good with a multimeter.There is either a wiring problem or a safety I missed.I have worked on mowers and tractors for years and dreaded wiring problems but usually figure out the problem.This one has me stumped for now.
Have you checked the fuses?
Let us know what you find! I say it's a bad switch or broken wire to/from said switch.
The plunger switches CAN be two way switches! If I were you, Id try to find a schematic. If no luck, check the switches and see if they have more than 2 wires! Check depressed and static positions! Trust me, these type switches will cause all kinds of headaches while troubleshooting if you don't know how they operate(ie: static sends power/ground here, and depressed sends it here)
I don't know if this will help or not, but my mower has similar issue, will die when engaging blades, only thing I can do to make it go is to turn the key in the position for mowing in reverse and push the button for the red light ON then can mow in both forward and reverse directions, wasn't like that when new but only thing I could figure out to get it going, I'm sure there is a switch or something that needs replacing but I don't know where or how so my work around is fine for now.
My Kubota BX tractor sometimes fails to shut down when I turn off with the key. The first time it happened I did about everything I could think of to shut er down. Removed battery cables, NO GOOD. Turned on the PTO for the front snow blower and got off the seat, NOPE!
Made a call to the dealer and they advised me to kink a fuel line. Tried that but still kept running. Those lines are hard to kink!! After getting hung up on from the dealer (the noisy running tractor may have had something to do with that) and about an hour and a half of high anxiety, I started feeling around under the forward left side of the rig. Found a small lever and pushed it forward. The tractor shut right down!!!!
A kill switch of all things and the goofy folks at the dealership didn't even know about it! I never did do anything to solve the problem and when the ole girl randomly fails to shut down I just push the kill switch.
Sounds like you have a loose and/or dirty ground somewhere(attached to whatever is supposed to turn the tractor off....IE key switch). Or maybe the switch is just dirty and needs sparying out with a contact cleaner!
I'm used to old tractors that do not require voltage to run or shut off. Apparently newer Kubota tractors have a solenoid that must be energized to kill the engine. Your issue is likely that solenoid or a blown fuse feeding that solenoid. Check for a blown fuse, that may fix your key off shut down problems. The old tried and true decompression knob works fine, so it's up to you if you wanna try and fix the electrical issue.
Suffocate the inlet for air..
is the kubota s diesel? the only way to shut off a diesel is to shut off the fuel. they used to use a pull cable or lever to do this, modern ones use a fuel cut off solenoid to shut the fuel off. no small engine (for usual yard equipment) uses a battery operated ignition like i posted before they shut the spark off by grounding the primary side of the ignition coil. some also use a fuel shut off solenoid that is battery operated on the bottom of the float bowel as a backup shutoff.
The old 2 stroke Detroit diesels had an emergency stop where a spring loaded plate would cut off the air supply.I never saw one do it but I heard stories of them uncontrollably running away and destroying the engine.
i have seen them "run away". scary when you are close to them.
Any updates on the zero turn mower?
My bet is on the brake switch! Must be one way to start and another for the PTO to engage. PTO will not engage with brake set or brake switch jumped closed.
Had to work last couple of days so I havent worked on the mower,but I will give that a try and let you know.Thanks
I think it's a ground problem.
Any updates on the mower problem? Inquiring minds wanna know!😁
Thought I had found it.It has a seat timer switch plus the regular seat safety switch.Unplugged the timer and the park brake and blade safety stated working. Replaced the timer made one pass cutting the yard and it died and none of the safeties would let it run. Back to the drawing board.
I would Google the model and search for the wiring diagram, most are free online. Thanks for the update.
Can't you remove all those safety switches and be done with it ?? I had pretty much the same problems several years back and removing all of the safety systems cured my problem, just don't let morons operate the mower (*remove keys after use*) or run the risk of being sued. Also I agree, get a wiring schematic and be careful of what you cut, double and triple check before doing so.
"Never do wrong to make a friend----or to keep one".....Robert E. Lee
you unhook the engine kill wire in the connector. and if you have a fuel cutoff in your float bowel you will have to provide that with power. engine will run but will be hard to shut off.
If this mower belonged to me I would have probably by passed the safeties,but it belongs to my daughter in laws grand dad. I had one a few years ago that I had to by pass the safeties and I had teenage sons here then.I told them to be careful and in the middle of the steering wheel I wrote with a permanent marker- NO SAFETIES-DFU- They knew what that meant.
I have the exact same machine and had the same problem twice.
First time the switch for the parking brake lever was bad. Found it with a multimeter.
Second time wires under the battery area dropped down and rubbed on a pulley/belt. They were the wires for the safety switch circuit.
It was a bad seat safety timer.Not the seat safety switch but a seat safety timer. It is an electronic device under the ignition switch and PTO switch.They must be like vehicle chips because no one I spoke with had one or knew when they would receive more. I guess I was lucky to find the last one at a small dealership for $106.
i bet they use that so the motor doesnt try to shut off if you bounce on the seat, or just lift lift your weight of the seat for an instant. it keeps the motor running until it makes sure you really did egress the seat. if that is true that would be at the top of the list of totally useless features to have.
Glad you found the problem
Glad it's fixed too! Now I'm curious about the purpose of the timer switch! If @varian is right, who decided how long it takes to step off and put your foot under the deck? Seems that switch COULD be bypassed, but with no schematic(and not hands on) I couldn't tell.
If the mower was running,you could unplug the timer an all the safeties would work.If you cut the mower off it would not start back until the timer was reconnected.
We had an Oliver tractor with 2 stroke Screaming Jimmy in it. It didn't run away often, but we always kept a coffee can that was almost the exact size to cover the air inlet. When it would happen, it would do it right at start up. So, we'd start it up with the can in hand just in case. It didn't rev fast, so one had time. It just didn't stop revving higher and higher. I so wish I had some pictures of that tractor in action. We used to cut silage with it at night and that exhaust manifold on up towards the turbo would be glowing red. The other tractors we had were kind of junk, old, worn out, and under powered (Ford 3000, International M and 400, 1850 Oliver, and this 1950 Oliver). This 2 stroke diesel could get some work done but it was loud. My dad still says it was that tractor that made him hard hearing. I don't doubt it.