K725KH no start

[whitetiger]

Why then did the dealer tell my customer they would not work on their product

I was not there so I do not know.

The Z700 series zero turn mower should take no more than 15 minutes to diagnose a no crank or no run complaint. They are that simple.

 

[TAFS]

I was not there so I do not know.

The Z700 series zero turn mower should take no more than 15 minutes to diagnose a no crank or no run complaint. They are that simple.

Well, I had three Kubota mechanics come to my shop and they left shaking their heads they could not find out why. So if you are so good at telling people things that you know nothing about anyone who states they can diagnose anything in 15 min is a bullshit artist. I know this because I had wanted to be a mechanic trying to get a job with us and could not even understand how to ohm check the system. I had people that I trust could not find out why parts are failing in this system. So I go with my many years of working on vehicles been doing this for over 30 years. I understand why the dealer could not repair that crap!!!

 

[whitetiger]

Well, I had three Kubota mechanics come to my shop and they left shaking their heads they could not find out why. So if you are so good at telling people things that you know nothing about anyone who states they can diagnose anything in 15 min is a bullshit artist. I know this because I had wanted to be a mechanic trying to get a job with us and could not even understand how to ohm check the system. I had people that I trust could not find out why parts are failing in this system. So I go with my many years of working on vehicles been doing this for over 30 years. I understand why the dealer could not repair that crap!!!

I have to go with my many years of working on vehicles part-time and being a large equipment tech for over 45 years with approximately 25 years of servicing and repairing Kubotas.
I currently work at a large well know Kubota dealership, we sell and service a lot of Z700 series zero-turn mowers. They are one of the simplest systems on a zero-turn mower.

I am sorry it damages your ego, but I, a Kubota Tech fully understand the simple electrical system on the Z700 mower.

 

[North Idaho Wolfman]

Well, I had three Kubota mechanics come to my shop and they left shaking their heads they could not find out why. So if you are so good at telling people things that you know nothing about anyone who states they can diagnose anything in 15 min is a bullshit artist. I know this because I had wanted to be a mechanic trying to get a job with us and could not even understand how to ohm check the system. I had people that I trust could not find out why parts are failing in this system. So I go with my many years of working on vehicles been doing this for over 30 years. I understand why the dealer could not repair that crap!!!

I don't allow insulting members!
How about you post an apology!

 

[TAFS]

I have to go with my many years of working on vehicles part-time and being a large equipment tech for over 45 years with approximately 25 years of servicing and repairing Kubotas.
I currently work at a large well know Kubota dealership, we sell and service a lot of Z700 series zero-turn mowers. They are one of the simplest systems on a zero-turn mower.

I am sorry it damages your ego, but I, a Kubota Tech fully understand the simple electrical system on the Z700 mower.

That is your opinion. But it takes time to check wires and components. Especially since it intermit. We checked and doubled check wire and components. we replaced the starter because it was stuck in the start position. Rectifier was fried. the time delay part next to the battery was bad. The seat switch finally failed. The oil pressure switch failed in the ohm check and did not get fired to the spark plug. Now I have a magneto that not giving me fire to the plug it worked before no it doesn't. I have no power to the fuel solenoid. The PTO is not engaging with the switch. I've read both wiring diagrams till I'm blue in the face. Then tell me what you think other than the WIRING IS SIMPLE... BECAUSE IT MY OPINION IT NOT THAT EASY IN THE REAL WORLD AND ALL THE redundancy WiRING is unnecessary.

 

[North Idaho Wolfman]

That is your opinion. But it takes time to check wires and components. Especially since it intermit. We checked and doubled check wire and components. we replaced the starter because it was stuck in the start position. Rectifier was fried. the time delay part next to the battery was bad. The seat switch finally failed. The oil pressure switch failed in the ohm check and did not get fired to the spark plug. Now I have a magneto that not giving me fire to the plug it worked before no it doesn't. I have no power to the fuel solenoid. The PTO is not engaging with the switch. I've read both wiring diagrams till I'm blue in the face. Then tell me what you think other than the WIRING IS SIMPLE... BECAUSE IT MY OPINION IT NOT THAT EASY IN THE REAL WORLD AND ALL THE redundancy WiRING is unnecessary.

That wasn't much of an apology???

Having so many fried / bad electrical parts seems almost incomprehensible.
The amount of electrical damage to that unit, sounds like it was either struck by lightning, or more likely someone hooked the battery up backwards and fried everything.

 

[TAFS]

That wasn't much of an apology???

Having so many fried / bad electrical parts seems almost incomprehensible.
The amount of electrical damage to that unit, sounds like it was either struck by lightning, or more likely someone hooked the battery up backwards and fried everything.

know you understand why I'm pissed at this zero turn

 

[GreensvilleJay]

1st , thank you to White tiger for posting the wiring diagram !
2nd, it IS simple. if you want overly complicated ,TRY to see what's involved in a Nissan Quashqai wiring for JUST the 'CANbus connections to the 8 or was it 9 computers......

query . when you said 'rectifier' was bad, do you mean the 'rectifier/regulator' or the 'rectifier' on the PTO connection ?

according to the wiring diagram, oil switch only goes to the 'oil' lamp, has no control over the engine

re: PTO unplug the connector, put +12 and gnd to the PTO..it should 'click'. If not, measure it's resistance, probably 3 ohms+-. Most draw about 4 amps..... If it does work this way then problem is wiring or switches.

re: fuel solenoid. unplug the 'engine' harness, put +12 to correct pin , and ground of course......you should hear solenoid 'click'. If not, measure it's resistance.

What I don't know is if YOU have to be sitting on the seat to do all these tests. THAT should be in the owners manual under 'how to start' section ??

All the 'extra' stuff...switches and relays are there to try to protect the idiots from hurting themselves or others. Can it be wired simpler, sure...only 2 wires to engine are needed.

 

[TAFS]

1st , thank you to White tiger for posting the wiring diagram !
2nd, it IS simple. if you want overly complicated ,TRY to see what's involved in a Nissan Quashqai wiring for JUST the 'CANbus connections to the 8 or was it 9 computers......

query . when you said 'rectifier' was bad, do you mean the 'rectifier/regulator' or the 'rectifier' on the PTO connection ?

according to the wiring diagram, oil switch only goes to the 'oil' lamp, has no control over the engine

re: PTO unplug the connector, put +12 and gnd to the PTO..it should 'click'. If not, measure it's resistance, probably 3 ohms+-. Most draw about 4 amps..... If it does work this way then problem is wiring or switches.

re: fuel solenoid. unplug the 'engine' harness, put +12 to correct pin , and ground of course......you should hear solenoid 'click'. If not, measure it's resistance.

What I don't know is if YOU have to be sitting on the seat to do all these tests. THAT should be in the owners manual under 'how to start' section ??

All the 'extra' stuff...switches and relays are there to try to protect the idiots from hurting themselves or others. Can it be wired simpler, sure...only 2 wires to engine are needed.

I love to deep dive into Electric car wiring or semi trucks Oh wait I've done that!! Wait I was alive when the first computer came out!!! Rebuilt the computer with my oscilloscope many times. Did custom builds understand wiring very well. Love doing all old cars. Then understanding how the new cars with computers and how to read their system. Wait I've been doing that for years. So I am not stupid I DO NOT WORK ON LAWNMOWERS but reading and understanding wiring and I have great knowledge of this. Plus I know how to design a wiring system!!!

First, there is no rectifier on the PTO it is a switch... that opens until powered up to engage the belt to turn the blades.

Then according to KOHLER, the Oil sentry is the Kill plus it runs that stupid light so that it kills both magnetos to kill the spark

The Caburerator solenoid should come from the Kubota wiring connection But last, doesn't there no power in this wire. Still not sure what going on Their four connections to this wire in the Kubota wiring diagram. PS You will get an OHMS reading of that solenoid on this carb This is a basic understanding of electric parts and how they work together... EVERYTHING HAS RESISTANCE VALUE PERIOD

No, you don't have to be in the seat Just zip tie the sensors or hot wire according to Kubota service manual.
So here is some advice You need to know whom you talk to, before writing stupid stuff

 

[GreensvilleJay]

OK, I'm using the schematic that WT posted in msg #18. Is the schematic in the service manual different ?

It clearly shows the rectifier in the PTO clutch wiring. So, if I assume you mean the 'regulator/rectifier' was bad.They are very robust devices, though prone to selfdestruct when you lose the ground on them.

I don't care what Kohler says, since it's the Kubota wiring that counts. 'Oil sentry' was an OPTION on some Kohler engines

If there's no voltage to the solenoid, follow the wire back to the 'stop' relay and whatever fuse /ign sw pins that feed it. Somewhere you've 'lost' the solid +12 that should be at the solenoid. What's the resistance value of the solenoid ? I could compare to the new one on the shelf ,or on another rider here.
As for the 4 connections, it could be they short the solenoid using a form c relay (stop),have seen that before.

I don't have the Kubota Service Manual, or the operator's manual, that's why I asked if you have to be on the seat. The answer is 'yes' according to your reply as 'zip tying and hot wiring' aren't normally done to run the machine.

You can easily bypass ALL of the Kubota wiring by disconnecting the engine harness. I've made several 'bench testing connectors' from old wiring harnesses or just use 2-3 test leads as jumpers. Course when the engine starts, one will fall off.......

Curious... what computer did you rebuild ? 8031,8052,1802,Z80,6800,8088, ? Heck I still have Intel 8008s in the basement

 

[North Idaho Wolfman]

So here is some advice You need to know whom you talk to, before writing stupid stuff

I think I've had about enough of this.
I personally don't care how smart you think you are, you have people that are trying to help you and all you can do is insult them.

 

[whitetiger]

OK, I'm using the schematic that WT posted in msg #18. Is the schematic in the service manual different ?

Jay, the wiring schematics I posted in #2 & #18 are the latest version from the Kubota Link Dealer Portal.

 

[lugbolt]

Worked on many

they are really, really simple electrical systems.

saw a lot of relays go south. Takes 30 seconds to swap them around, takes a few minutes to get to them.

but for the most part they're really simple mowers which is good for lawn services. Less downtime.

 

[GreensvilleJay]

Thanks WT for letting me know ! In the past I've seen 'updated' schematics in other makers WSM compared to owner's manuals,usually based on serial number ,where a 'change or two' was done.

 

[TAFS]

I think I've had about enough of this.
I personally don't care how smart you think you are, you have people that are trying to help you and all you can do is insult them.

I had enough of the insult myself. I have been polite to most of the people. I got one that says I'm sorry I bruised your ego, telling me to read the wiring diagram over and over. If they want to help don't batter me with stupid stuff. I asked for another thing, not stuff that I have already been doing. This has been a two-way street!!!!

 

[North Idaho Wolfman]

I had enough of the insult myself. I have been polite to most of the people. I got one that says I'm sorry I bruised your ego, telling me to read the wiring diagram over and over. If they want to help don't batter me with stupid stuff. I asked for another thing, not stuff that I have already been doing. This has been a two-way street!!!!

You've had 3 highly trained Kubota techs telling you, it's a simple system, yet all you want to do is insult us for telling you that?

It has 2 wires that will let it run or not:
Magnetos: Black / White with no connection to run and (-) ground to stop.
Fuel solenoid: Yellow / White for the (+) Positive to run.
Starter solenoid: Trigger is Blue / Red

If you're cranking it and there is No connection on the Black / White then you should have spark, if you don't have spark you have bad magnetos, or a bad adjustment.
If you feed power to Yellow / White you should get fuel.

It doesn't get much simpler than that.

 

[jeffmcCath92]

Thanks for the useful info.

 

[TAFS]

You've had 3 highly trained Kubota techs telling you, it's a simple system, yet all you want to do is insult us for telling you that?

It has 2 wires that will let it run or not:
Magnetos: Black / White with no connection to run and (-) ground to stop.
Fuel solenoid: Yellow / White for the (+) Positive to run.
Starter solenoid: Trigger is Blue / Red

If you're cranking it and there is No connection on the Black / White then you should have spark, if you don't have spark you have bad magnetos, or a bad adjustment.
If you feed power to Yellow / White you should get fuel.

It doesn't get much simpler than that.

You wrote this!!!
It has 2 wires that will let it run or not:
Magnetos: Black / White with no connection to run and (-) ground to stop.
Fuel solenoid: Yellow / White for the (+) Positive to run.
Starter solenoid: Trigger is Blue / Red

First 1 There is no black wire running here... It grey
Second The fuel solenoid also does not have a yellow and white. It's red and black. It is also a two-barrel carb. The red is hot and the black wire goes to the ground
Third Start This wire is Violet for the starter trigger.

I'm not sure where you got the colors but does not match what Koler has for their motor IT does not matter what Kubota has in their wiring diagram. They could have different wires to connect to the Kohler cv742-3011 motor but that is a different subject.

Let me add this The oil switch on the sensor also kills the motor with the Kohler wiring diagram and in their wiring diagram. This also kills the spark. I tested that did not spark me at all until I ground that wire now there is a spark This wire is hot and the sensor ground it and it is green.

I add the Kohler wiring diagram page 32-33

 

[GreensvilleJay]

I'd like to see pictures of the actual wiring, especially the engine connector and the ignition switch as well as oil pressure wiring.
The oil switch, even in the Kohler 'suggested' wiring, goes to the oil light then the acc+ on the ign switch, no connection to the magnetos. The oil switch is NC (normally closed). If it was wired to the mag..so....NO spark..until engine starts and makes oil pressure,but can't start as mag is grounded.
You can't go by the Kohler wiring, you have to use the Kubota wiring. Kohler only makes the engine up to their 6 pin connector, after that it's the OEM who decides how to interface to what features the engine may have.

 

[JP_Austin]

Agree I would totally isolate the engine. It's power and ground. As long as the fuse is good it should be able to hot wire and run. I had a Briggs that had a bad CAM once that was difficult to diagnose but if your a mechanic than the general engine tech should not be a mystery.

Timing, compression, fuel and spark should make it pop. Of course don't forget that 99% of small engine troubles are caused by the poor ethanol fuel that attracts water. You may be trying to light water on fire if you have not drained the tank. Fresh non ethanol fuel is absolutely required and a fundamental of any small engine debug.