K725KH no start

North Idaho Wolfman

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Equipment
L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
Jun 9, 2013
28,781
5,166
113
Sandpoint, ID
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
Well you know FAR more than all of us, and seem to have it all figured out, so why isn't it fixed and running? :unsure:
 
Last edited:

TAFS

New member

Equipment
K725KN
Apr 20, 2024
21
0
1
Belton, TX
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.
Well, you think that. But I tested that idea I tried starting it with the original oil sensor and my sparkplug gap tester. As I hot wire the motor I never got a spark. I retested and then unplugged it Then ground that green wire and got a spark at .035. ( J ) states that OIl sentry Kill ( green) so the green wire is the only wire that says kill.

The only wire that is not getting a 12-volt power is the carb sensor. we tested the Kubota all three safety systems relays and we have power from them. But yet we cannot start the motor with the switch. However even hot wiring the motor it still will not start that way either. The only other thing that seems not to work is the PTO on the motor it is either on or off with the key is turned or not

I understand wiring and how to test it and read a wiring harness. I have never worked on a zero turn before... So of the people on here that it's a simple wiring. I on the other hand that it's too dam redundant for a lawn mower!! I rather rewire a Polaris GEM 2 Electric golf cart or automotive wiring.

So repeat myself I do want the help but I need some ideas to try Please don't tell me to re-read the wiring harness give me something to look for and test.

We replaced the Timer delay., replaced all 4 relays, the Oil sensor, and the Seat sensor, We replaced the motor rectifier because it was melted. I also replacing one on the magnetos because it not sparking enough. Then we replaced the starter switch due to the key breaking off. The PTO we replaced it because of a continuity test it failed.
 

TAFS

New member

Equipment
K725KN
Apr 20, 2024
21
0
1
Belton, TX
Well you know FAR more than all of us, and seem to have it all figured out, so why isn't it fixed and running? :unsure:
I do not do lawnmowers I do know how to read wiring harnesses. I like the help since I do not work on Kubota of any type. This is not what our shop works on we do a lot of semis, automotive. golf carts and misc stuff. But I try to stay away from lawnmowers, small equipment, and heaving to farming stuff... If you have an idea or something I can test or check I'm up for it. but I'm not up to having someone on just to tell me to reread the wiring harness manual. The thing I HATE IS INTERMITTENT ISSUE. I believe this is what I got myself into...
So I will be blunt If you have a suggestion that I have
NOT tried then send it my way!!!
 

GreensvilleJay

Well-known member

Equipment
BX23-S,57 A-C D-14,58 A-C D-14, 57 A-C D-14,tiller,cults,Millcreek 25G spreader,
Apr 2, 2019
9,968
4,093
113
Greensville,Ontario,Canada
Easy way to get engine to run

1) disconnect the 6 pin engine harness connector
2) jumper +12 to the fuel solenoid pin on engine side of the connector
3) jumper +12 to starter solenoid coil

you'll spin the engine, have gas and spark
 

TAFS

New member

Equipment
K725KN
Apr 20, 2024
21
0
1
Belton, TX
Easy way to get engine to run

1) disconnect the 6 pin engine harness connector
2) jumper +12 to the fuel solenoid pin on engine side of the connector
3) jumper +12 to starter solenoid coil

you'll spin the engine, have gas and spark
Thank You!!! I will try that tomorrow after I replace one of the magnetos.
 

TAFS

New member

Equipment
K725KN
Apr 20, 2024
21
0
1
Belton, TX
placingthe new magneto
Easy way to get engine to run

1) disconnect the 6 pin engine harness connector
2) jumper +12 to the fuel solenoid pin on engine side of the connector
3) jumper +12 to starter solenoid coil

you'll spin the engine, have gas and spark
Thank you. After placing the new magneto and unplugging the Kubota wiring harness the motor turned over and it ran great.
So what do you think we need to do to get the Kubota to fire this motor?
 

GreensvilleJay

Well-known member

Equipment
BX23-S,57 A-C D-14,58 A-C D-14, 57 A-C D-14,tiller,cults,Millcreek 25G spreader,
Apr 2, 2019
9,968
4,093
113
Greensville,Ontario,Canada
divide and conquor usually wins.
Now you KNOW the engine and it's wiring are GOOD.

next step.

With engine harness disconnected, there's only 3 signals to deal with.
1) +12 to AD solenoid
check the pin for +12 with key 'on'
2) mag kill
check the pin for continuity to ground with key 'off', open when key 'on'
3) oil light
with key on, ground the 'oil switch' pin, light should come on.
 

jaxs

Active member

Equipment
B1750HST
Jun 22, 2023
436
215
43
Texas
placingthe new magneto
Thank you. After placing the new magneto and unplugging the Kubota wiring harness the motor turned over and it ran great.
So what do you think we need to do to get the Kubota to fire this motor?
Know wut? With your understanding of what is required I suggest you re-wire it in a fashion the makes sense rather than straightening out Kubota's Rube Goldberg.
 

TAFS

New member

Equipment
K725KN
Apr 20, 2024
21
0
1
Belton, TX
Know wut? With your understanding of what is required I suggest you re-wire it in a fashion the makes sense rather than straightening out Kubota's Rube Goldberg.
I love to do that!! But this is not my equipment I have to ask the customer.... We have found that by keeping the wiring harness in place the key switch is on. Then we ran a hot wire to the signal wire and the motor wire so we could start the motor. Then everything worked the pto switch on and turn the blades. The key would kill when turned to the key off and it kills the motor. this was with the seat switch and the parking switch closed with zip ties
 

TAFS

New member

Equipment
K725KN
Apr 20, 2024
21
0
1
Belton, TX
divide and conquor usually wins.
Now you KNOW the engine and it's wiring are GOOD.

next step.

With engine harness disconnected, there's only 3 signals to deal with.
1) +12 to AD solenoid
check the pin for +12 with key 'on'
2) mag kill
check the pin for continuity to ground with key 'off', open when key 'on'
3) oil light
with key on, ground the 'oil switch' pin, light should come on.
This did not do anything... Please read my other post to see how we got it to start
 

GreensvilleJay

Well-known member

Equipment
BX23-S,57 A-C D-14,58 A-C D-14, 57 A-C D-14,tiller,cults,Millcreek 25G spreader,
Apr 2, 2019
9,968
4,093
113
Greensville,Ontario,Canada
hmm...40-50 posts ago you said you replaced the ignition switch. Any chance it's the wrong one ?
Always best to ring it out and confirm as 'if made by INDAK they all look alike'.