G2460G Riding Mower Has No Spark

DLStryker

New member
Aug 29, 2021
21
0
1
Dallas, TX
A new to me G2460R rider has no spark. The engine is the WG752-ES-24G 3 cylinder gas engine.

I have the WSM for the G2460 mower and it is close to worthless in troubleshooting electrical issues.

With the key switch on, I have 12V at the negative terminal and positive terminal both of the coil. When I crank the engine, the 12v positive remains "on" at both the positive and the negative terminal of the coil. I have tested the resistance of both the Primary coil and Secondary coil and they are within range. When I crank the engine and place the coil wire coming directly out of the top of the coil close to ground, I get no spark.

Any ideas?

Is there a shop manual that is better for chasing electrical issues with this mower?
 

lugbolt

Well-known member

Equipment
ZG127S-54
Oct 15, 2015
3,104
433
83
Mid, South, USA
it sounds like you are not getting a pulse to the neg side of the coil. If that is the case, you should understand the system. What causes the pulse?

It has a distributor, cute little thing! Anyway inside the distributor is an ignition module that generates the ground pulse that "fires" the coil. That pulse is generated by the reluctor inside the distributor, aka "pickup". With that we have 3 things to look at. Wiring between the module and the coil (if you have +12v I think the wiring is probably ok). Module itself--of which I think there is no conclusive test for, and it's a similar setup to a GM HEI distributor wherein the module sits inside the cap, is subject to heat, thus failure. Some Ford TFI's had the similar setup, I own two of them and I carry a spare TFI module for that reason. Third thing that comes to my mind is the distributor itself (possible pickup failure). Or rotor/cap.

So here is what I would do. First, take the cap off of the distributor and roll the engine over. Does the rotor spin? If it does, the drive assembly is probably fine.. Look at the rotor. Is the tip of the rotor torn up/burnt up/corroded? If so, replace it. If not, that leaves you with the module and pickup as the most likely culprit. Kubota offers the module with the pickup as an assembly (12692-68602). The rotor is a service item and should be replaced every so often, so even if it's ok, I'd probably recommend replacing it as well. Perhaps the cap too since it often wears at the contacts. I don't know how hard it is to get to the distributor, or how much it costs, but honestly if it's not all that expensive I'd probably just replace the entire thing as an assembly.
 

DLStryker

New member
Aug 29, 2021
21
0
1
Dallas, TX
it sounds like you are not getting a pulse to the neg side of the coil. If that is the case, you should understand the system. What causes the pulse?

It has a distributor, cute little thing! Anyway inside the distributor is an ignition module that generates the ground pulse that "fires" the coil. That pulse is generated by the reluctor inside the distributor, aka "pickup". With that we have 3 things to look at. Wiring between the module and the coil (if you have +12v I think the wiring is probably ok). Module itself--of which I think there is no conclusive test for, and it's a similar setup to a GM HEI distributor wherein the module sits inside the cap, is subject to heat, thus failure. Some Ford TFI's had the similar setup, I own two of them and I carry a spare TFI module for that reason. Third thing that comes to my mind is the distributor itself (possible pickup failure). Or rotor/cap.

So here is what I would do. First, take the cap off of the distributor and roll the engine over. Does the rotor spin? If it does, the drive assembly is probably fine.. Look at the rotor. Is the tip of the rotor torn up/burnt up/corroded? If so, replace it. If not, that leaves you with the module and pickup as the most likely culprit. Kubota offers the module with the pickup as an assembly (12692-68602). The rotor is a service item and should be replaced every so often, so even if it's ok, I'd probably recommend replacing it as well. Perhaps the cap too since it often wears at the contacts. I don't know how hard it is to get to the distributor, or how much it costs, but honestly if it's not all that expensive I'd probably just replace the entire thing as an assembly.
Thank you for the informative reply Lugbolt! If I understand the WG752 WSM correctly, the wire coming out of the distributor and going to the Primary coil, when the engine is cranking, should be alternating between 12V and no voltage. When the Primary coil sees "no voltage", a high voltage should be produced by the secondary coil. This is the current that ignites the spark plug. That is my explanation if I understand the verbiage correctly.

For testing, my question is, should a standard Volt Ohm Meter show the alternating between 12V and no voltage of the wire coming out of the distributor and going to the Primary coil? I am trying to determine if I can test this function.

By the way, the ignition ignitor module is VERY expensive!!! $450+. That is why I am trying to do more testing. I see I can get an entire genuine Kubota distributor for $335. I will go that way if that seems like that is the solution.
 

Roadworthy

Well-known member
Lifetime Member

Equipment
L2501 HST
Aug 17, 2019
1,081
176
63
Benton City, WA
I'm not sure of your hardware and this may not apply but if your take the coil from an older car it has three connections. The case is ground. The primary may be marked + and -. The + is on whenever the ignition is on. The grounded case is connected to the base of the spark plugs. The secondary (high voltage) lead of the coil as connected to spark plugs one at a time by the distributor but if connected to the cap of one plug that would do for a test. When the - lead of the coil is touched to ground a spark is generated thus showing the coil and plug work. Holding it grounded will not make more spark. You have discharged the energy built up in the coil. You must disconnect it from ground then ground it again to get another spark. The firing happens due to building up and collapsing an electrical field within the coil. It's kind of like a chopped DC. Some voltmeters can deal with this and others cannot.
 

lugbolt

Well-known member

Equipment
ZG127S-54
Oct 15, 2015
3,104
433
83
Mid, South, USA
For testing, my question is, should a standard Volt Ohm Meter show the alternating between 12V and no voltage of the wire coming out of the distributor and going to the Primary coil?

No it "pulses" so quickly that a volt meter won't show it. You're far better off using an LED test light. An incandescent usually won't work either, it takes time for the filament to get hot and illuminate and you can't usually see the pulse. LED only as it lights up a LOT quicker.
 

TheOldHokie

Active member

Equipment
L3901/LA520, B7200DT/LA1630, G2160/RCK60, G2460/RCK60
Apr 6, 2021
408
149
43
Myersville, MD
I'm not sure of your hardware and this may not apply but if your take the coil from an older car it has three connections. The case is ground. The primary may be marked + and -. The + is on whenever the ignition is on. The grounded case is connected to the base of the spark plugs. The secondary (high voltage) lead of the coil as connected to spark plugs one at a time by the distributor but if connected to the cap of one plug that would do for a test. When the - lead of the coil is touched to ground a spark is generated thus showing the coil and plug work. Holding it grounded will not make more spark. You have discharged the energy built up in the coil. You must disconnect it from ground then ground it again to get another spark. The firing happens due to building up and collapsing an electrical field within the coil. It's kind of like a chopped DC. Some voltmeters can deal with this and others cannot.
Dan
Thank you for the informative reply Lugbolt! If I understand the WG752 WSM correctly, the wire coming out of the distributor and going to the Primary coil, when the engine is cranking, should be alternating between 12V and no voltage. When the Primary coil sees "no voltage", a high voltage should be produced by the secondary coil. This is the current that ignites the spark plug. That is my explanation if I understand the verbiage correctly.

For testing, my question is, should a standard Volt Ohm Meter show the alternating between 12V and no voltage of the wire coming out of the distributor and going to the Primary coil? I am trying to determine if I can test this function.

By the way, the ignition ignitor module is VERY expensive!!! $450+. That is why I am trying to do more testing. I see I can get an entire genuine Kubota distributor for $335. I will go that way if that seems like that is the solution. Ok
I dont know the specifics of the G2460 ignition but the ignitor is typically a simple solid state switch. You can test it with a voltmeter connected to the coil primary just like you would mechanical contact breaker points. If it switched it is working. Here is a typical test setup.

Dan
 

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DLStryker

New member
Aug 29, 2021
21
0
1
Dallas, TX
No it "pulses" so quickly that a volt meter won't show it. You're far better off using an LED test light. An incandescent usually won't work either, it takes time for the filament to get hot and illuminate and you can't usually see the pulse. LED only as it lights up a LOT quicker.
So from testing and not finding any protection circuits shutting off the ignition, I am 99% sure the Ignitor is the problem. I was able to order an entire distributor with ignitor installed along wit new rotor and cap for about $100 less than the Ignitor alone. $336 for Kubota OEM distributor vs. $450 for Ignitor by itself.

I have the question, how do I remove the mechanism that protects the distributor bolt? The anti tampering device? The WSM says "set the plug draw-out bolt to the tamper plug and draw out the tamper plug." This instructions from the WSM are attached.
 

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TheOldHokie

Active member

Equipment
L3901/LA520, B7200DT/LA1630, G2160/RCK60, G2460/RCK60
Apr 6, 2021
408
149
43
Myersville, MD
Cant help with the bolt but as a fellow G2460 owner I would like to know where you found the distributor for that price. I am seeing $700+.

Dan
 

DLStryker

New member
Aug 29, 2021
21
0
1
Dallas, TX
Well... all is fixed now. The exciter module inside the distributor was in fact the problem. Thank you all for your input. It ended up being cheaper to buy an entire distributor that it was for just the module. So $368 to fix.

Pic of the old attached.
 

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