"New" Mower. Tell me How I Got Cheated

[Mr Haney]

He put tires on it, as I said. He had no idea where the anti-scalp parts were.

The parts diagram for the cutting height dial ("cam dial" K3181-44430) appears to show that the shaft under it will come off if I can get the cotter pin out, but the shaft is currently turned so it is not going to be easy to get at that pin. The deck needs to be raised so I can turn the dial, but I can't start the mower, so I have to take care of that before I can remove the dial.

 

[Mr Haney]

I am wondering if the starter solenoid is bad. All the lights turn on, I hear a click, and I hear clicks when I put all the safety switches in the right positions. I haven't gotten at them to test them because getting at them is hard.

The starter pinion doesn't move, and the starter doesn't turn.

How do I bypass the solenoid to start the mower? It stops with the key, so I have some hope it won't run away.

The starter is on the left side.

 

[Mr Haney]

Here is a sitrep.

The starter has a big red terminal and a smaller blue one. I shorted these terminals. The starter ran just fine, but the pinion did not extend.

The battery is at 12.8V, and it was installed this year.

Wondering if the ignition switch is kooky. It is also new.

 

[whitetiger]

I believe I found the serial number. There is a number on a decal on the lower part of the ROPS; 37***, I think.

That is the ROPS model and serial number.
The mower model and serial number are on a decal, which is located under the RH fender/operator's platform, stuck onto the mower frame.

To jump the starter, you short between the battery cable and the spade on the solenoid with a BW wire plugged onto it.

 

[Mr Haney]

New info.

I found out how to jump the starter correctly, in case anyone else wants to know. I jumped the red starter terminal (battery +) to the little male spade connector on the starter. The starter functioned just fine, and the mower ran. I had to use the fuel cutoff to stop it, though.

My best guess now is that the ignition switch is in bad shape, since it is more exposed to the weather than the safety switches and other circuitry. Also, it's right by the clock, which is dead.

I can raise the deck by starting the engine directly, so I plan to raise it to turn the cotter pin on the height dial shaft to where I can remove it. Then I'll see if I can get the cutting height dial off by yanking the cotter pin. If not, I'll try loosening the dial with a hair dryer. If that doesn't work, I'll adjust the deck to the height I like, rip the dial off by brute force, and then get at the ignition switch and the PTO and right lever switches to get everything working. I'll buy a new dial for $11 and put some lube on the lever before installing it.

Maybe I'll try the hair dryer first. Anyway, now I have a plan, and I don't need a starter. Incidentally, it looks like NipponDenso makes new starters that sell for $234 on Ebay, so don't pay $400+ for one from a Kubota dealer.

After replacing the old safety switch on the brake, I tested it, and it's fine, so now I have an extra switch in case I find a bad one.

There are three relays under the plated cover under the seat, and one of them runs the starter. They look cheap, and they are easy to get at, so if going through the switches doesn't get me anywhere, I can replace the relay.

 

[whitetiger]

It would be nice to have new control panel decals, but they don't pop up for sale when I look.

They are listed under the Labels tab.
K3181-65212 LABEL, INDICATOR

 

[Mr Haney]

Thanks. I found them online days ago.

 

[Mr Haney]

That is the ROPS model and serial number.
The mower model and serial number are on a decal, which is located under the RH fender/operator's platform, stuck onto the mower frame.

Thanks for the info. I found it, and it sets me back a few years. I will ask Kubota.

 

[Mr Haney]

In case anyone is wondering, the serial number on this mower is very hard to see when the deck is raised.

I had a horrid time working on the starting problem today. I should have checked the easy things first, but the PTO safety switch looked so likely, I could not stay away from it. I still haven't checked the motion control safety switches, which are easy to replace, but I made myself miserable changing the PTO and brake safety switches, which turned out to be irrelevant.

The way to get at the PTO safety switch is to loosen the fender and gas tank to make room for your hand. It's just 5 screws, if memory serves. Removing the PTO switch screws is a pretty bad experience.

My new plan is to check the connection on the backyard seat bypass the original owner did. This should have been my first step. After that, the motion control safety switches. Then the ignition switch, which appears to be an unpleasant job. Then the starter relay.

If I get nowhere, I am planning to put a momentary switch between a hot wire and the starting solenoid and keep it there until I figure out what's up with the mower.

This info might help others:

The seat switch is closed when the motor starts, so shorting it with a splice should bypass it effectively.

The arm switches are closed when the motor starts, so same deal.

To check a relay, the manual says, ""Measure the resistance with an ohmmeter across the terminal 85 (2) to terminal 86 (5), terminal 87 (1) to terminal 87a (3) and terminal 87 (1) to terminal 30 (4)." Manual page 5-S17."

Ignition: It looks like you want continuity between red (to battery hot) and black/yellow (to starter relay) contacts when the key is in the start position.

Feel free to double-check my conclusions.

 

[Mr Haney]

I found the seat switch wires down near the relay box. They had been twisted together and covered with duck tape, of all things. The connection was okay, though. I redid it with a wire nut, and I will go back and do it right with solder and shrink tubing. It will look like it came from the factory that way.

Moving on to the next thing on my list, I pulled the starter relay and found one of the resistances was infinite when it should have been zero, so it looks like the relay is no good. I have a new one coming. Ten bucks. Meanwhile, I guess I can hotwire the mower in order to fix my yard.

 

[Mr Haney]

Here is info that might be interesting for anyone who is cleaning up one of these machines.

The armrest pads on this mower were in bad shape. Each one is held on by two 1/4"-20 1/2" oxide-finish flange screws. I figured the pads would be a breeze to replace. Four screws out. Four screws in.

My new $51-each pads came without screws. The screws do not appear in the online parts list, so you can't buy them separately unless maybe you find the part number elsewhere. No problem. I would just use the old screws.

I had to use an impact driver to get the screws out. They were completely galled in place. Nice. When I removed them, the threads that were supposed to go into the new pads were destroyed. No problem. I would just buy new screws at Tractor Supply.

I checked the threads with a Thread Detective and a conventional pitch gauge, and this is how I learned they were 1/4"-20.

Tractor Supply did not have flanged 1/4"-20 1/2" screws. No problem. I bought stainless screws and flat washers.

I tried to drive the screws into the threaded holes on the pads, and they just spun. The rubber coating on the pads partially covered the holes. No problem. I would just work around it.

The rubber was not the problem. Kubota apparently does not know how to thread a 1/4" hole (no, it's not M6). My new screws could not catch the pre-boogered threads. No problem. I would clean the threads with a gun tap.

The gun tap was so long, I was afraid it would go through the top of the pads. No problem. I have bottoming taps.

I had to use gun taps to start redoing the threads, because bottoming taps would not catch reliably, and then I followed carefully with bottoming taps. I put blue Loctite on each screw to reduce galling in case I have to replace the new pads when I'm 90. Long story short, a 10-minute job took at least an hour, not including a trip to Tractor Supply.

My advice to handy people is to make your own pads out of scrap wood and use truck bed coating to paint them a convincing black. Or just remove your armrests. They don't seem very useful.

 

[Mr Haney]

I don't think the relay is the problem. I switched them around, and the mower still had no interest in starting. I also cleaned up the contacts inside the ignition switch, bringing the resistance down from 300K to 0. I went through the remaining safety switches.

It's starting to look like the controller is the weak link. The mower doesn't like to shut down with the key, and that's likely to be a relay or the controller.

I haven't taken all three relays out to test them. I had to get the yard done, so I quit tinkering and hot-wired the mower. It slowed down by itself several times.

Three new relays and two fuel filters will be here Monday. I'm going to pop the new relays in instead of testing the old ones, since it's a lot easier. After that, the new filters go in. The random RPM drops could be the filters but could also be the ECM (controller), unless I am misinformed.

If the new relays don't work, I may go ahead and buy a new ECM. The cost of having the mower hauled to the dealer, combined with the likelihood they will keep it for at least a month, plus the dealer's labor rate, make spending for a new ECM look like a better idea. There isn't much of anything left that could be faulty. I went through the fuses and everything.

I don't think the guy who sold me the mower had any idea it had this issue, because it started just fine for him two or three times when he was showing it to me. My hard luck, I guess.

 

[fried1765]

The first mow went really well. I did take out a couple of shrubs and part of a piece of ground cover, but I'll get the hang of it. I had to quit because it rained.

Before I could mow, I had to dump a lot of fluid. The seller overfilled the transmission. I had to use an oil sucker. I am no good with a siphon. On the up side, the fluid doesn't taste that bad.

I would estimate he was off by half a gallon. It hurt to dump that expensive SUDT2 on a bothersome stump, but I was not able to catch it all in a clean container.

I have trouble getting the mower to crank. At first, I had the PTO engaged and didn't know it; the relevant decal is gone, so decals are on my Messick's list. The second time I had trouble, the mower started when I reduced the throttle. I don't know if there is a cutout for a high throttle setting or what. I also fiddled with the seat a little. This mower's lawyer switch is cut, so it could be that something in there is shorting. I would have cut it myself, so I am happy the switch is dead.

People say these things don't give the best quality of cut, but I guess those guys are pros. I am just trying to hold the jungle back, and the cut I got looks fantastic to me. No windrows, no clumps. Nice and flat. I don't think I need the scalping assemblies. I didn't hit any concrete.

The deck really blasted cut material out. I have not covered the chute yet. Based on what I saw, I think G6 blades and a chute cover will handle my leaf-mulching just fine. For that matter, as it is, it may be good enough. The new blades are coming anyway.

The speed was wonderful. Seemed like it took half as long as the John Deere. It would be faster if I knew how to use a zero-turn. I kept slowing it down to keep from hitting things.

The seat suspension is nothing to write home about, but I don't sit on it all day, so I'll get over it.

I see why the first owner threw out the pulley covers. This thing is a bear to clean after mowing. The deck was buried in grass, leaves, and dirt, and it went in under the floorboard. I opened the floorboard hatch and spent a lot of time blowing crud out with a small leaf blower.

I thought the ROPS might be bent because the clamp knobs were mangled, but I got them off with a strap wrench, and the ROPS is fine. I plan to keep it folded most of the time because I have to mow under trees.

It is obvious this mower has seen very little rain but a good deal of sun, so I think the owner kept it in a pole barn with no walls. That is common down here. The lever grips are bleached, as are the seat belts. I think the sun is what ate the armrests. The sun is why the mower's appearance could be better.

I believe I found the serial number. There is a number on a decal on the lower part of the ROPS; 37***, I think. Manufactured in Fayetteville and so on.

I have not opened up the control panel to see if the hour meter wiring is okay, but since the idiot lights use the same wires, I would guess that it is. I suppose I'll have to get a new electronic meter. The one I have is mechanical.

My Messick's cart is filling up. I would go buy this stuff locally, but two big companies have taken over the Kubota business here, and they can't be bothered to create a decent website.

View attachment 157525

You can never go wrong with Messicks

 

[JasonW]

Was you able to download the service manual and look at the wiring diagram?
I may have missed something but what part are you calling the controller/ECM? These don’t have a computer. Really the only electronics is the fuel cut off solenoid.

Edit. I see it now on Messicks diagrams.

 

[PaulL]

There must be some diagnostic logic that would let you determine whether it's the controller or not.

If you know what the inputs to the controller should be, you can check them one by one and eliminate a faulty input as a cause. Presumably there are some circuits that need to be open (safety switches maybe), and some that need to be closed. And then check the outputs from the controller. If it's supposed to put power on specific circuits, and it does, then it's working.

Controllers aren't cheap, and swapping one just to see isn't a great idea. If you are going to, then make sure you buy one from a place that'll take it back if it isn't the cause - if you swap it in and nothing gets better, then take it out again and send it back. But if it were me I'd spend the time checking every input and output first, it's probably only a couple of hours of work with a multimeter.

 

[Mr Haney]

There must be some diagnostic logic that would let you determine whether it's the controller or not.

If you know what the inputs to the controller should be, you can check them one by one and eliminate a faulty input as a cause. Presumably there are some circuits that need to be open (safety switches maybe), and some that need to be closed. And then check the outputs from the controller. If it's supposed to put power on specific circuits, and it does, then it's working.

Controllers aren't cheap, and swapping one just to see isn't a great idea. If you are going to, then make sure you buy one from a place that'll take it back if it isn't the cause - if you swap it in and nothing gets better, then take it out again and send it back. But if it were me I'd spend the time checking every input and output first, it's probably only a couple of hours of work with a multimeter.

It appears the controller doesn't do anything good for the mower itself. The schematics show connections to the lawyer switches and shut-off solenoid, but not the engine, transmission, or gauges.

I've seen claims that it controls the engine and other things, but since there are no connections, that appears to be untrue. It's not making the engine run smooth, controlling the injection, or anything else like that, as far as I can tell.

Getting at the wiring around the controller is not a pleasant job, so I think it will take a lot more than two hours if I have to do it. If it's really two hours, it will be a dirty, hot two hours bending over most of the time.

There is no schematic for the controller. That is annoying. It would be nice to know exactly what's happening in there. It would also be nice if dealers could bench-test a $340 proprietary part, but people on the web say they can't.

It would be great if it turned out the ECM ground was bad and easily fixed. Still hoping for the best.

 

[PaulL]

You may be able to reverse engineer what it should be doing, particularly if it's mostly checking the safety switches and deciding whether to let you start / whether to cut the fuel if you're clearly doing something unsafe (as defined by California legislators).

I haven't seen that unit, but seems to me there's a bunch of safety switches going in - all of which are either normally open or normally closed. And then there's something for the starter relay and something for the fuel cutout. Fuel cutouts are also either normally open or normally closed. All those things should be able to be figured out by thinking and measuring a bit. And a lot of them might be able to be measured at the switch or the starter relay or the fuel solenoid.

If they all measure good where you can get to them, then it may be worth trying to measure them on the ECM itself to make sure you don't have a bad wire or a bad connection. And disconnecting, cleaning, reconnecting all the connections is probably a reasonable spend of time also - it's no more work than putting a new ECM in would be, but it's less expensive.

If all the ECM is doing is the killjoy switches, I'd also question whether it's possible to just delete it, and thereby bypass every safety switch in one go. Of course that would be incredibly unwise, and you'd probably die a day after doing it through some incredibly unfortunate mishap, so definitely don't follow my advice.

(I actually am OK with my safety switches, I like that the mower stops spinning if you get out of the seat, and that you can't start the PTO without explicitly lifting the seat. I don't want some kid to borrow my tractor and cut his foot off by jumping off / the stories about what goes wrong with PTO shafts are horrific. Messicks have a really good video with a guy with one leg who thought that PTO safety guards were optional - of course, he had two legs when he thought that. But I'm not sure I'd spend $340 and some indeterminate amount of time trying to keep them going if they were playing up)

 

[GreensvilleJay]

re: There is no schematic for the controller. That is annoying. It would be nice to know exactly what's happening in there. It would also be nice if dealers could bench-test a $340 proprietary part, but people on the web say they can't.

It'd be nice if 'someone' opened up the controller case, so we (OK, me) could see what's inside......
As for testing.... it'd be easy to mockup a few switches and a light or two, then test using a 'truth table'.