Kubota M62 Cranks, Won't Start, Backhoe/3PH Interlock Issue (SOLVED!)

[RedNeckGeek]

Kubota M62 Tractor Loader Backhoe, 279 hours. It went through a regeneration cycle yesterday, sitting parked in the driveway. Everything seemed normal after that, moved it over to the backhoe and got the hoses hooked up, and the tractor wouldn't start. Cranks fine, just won't catch and run all the time. If it sits a long time, it'll start, but runs very poorly, then won't restart if tried.

I've replaced both air filters, and also the fuel filter. Bled the air out of the fuel system several times, still no start. I have the owner's manual and the factory service manual, and neither one gives much guidance for a no start situation. Any ideas here to start tracking down the problem?

Here's a video of the instrument cluster during a start attempt. Notice the change in engine sound a few seconds in.

Thanks in advance...

 

[RickB]

279 hours? Maybe a warranty problem?

 

[RedNeckGeek]

279 hours? Maybe a warranty problem?

No such luck. It was out of warranty when I got it.

 

[RickB]

Over 5 years old with those hours? Wow.

 

[mikester]

Sounds like it could be a lack of fuel, maybe a clogged filter or the valve is off

 

[Smokeydog]

When you connected the backhoe hoses did you also change the two valves under the seat? Tractor deadheading the hydraulics?

Slime in stored or low hour equipment diesel fuel always a problem in warm humid climates that has to be considered.

 

[fried1765]

Kubota M62 Tractor Loader Backhoe, 279 hours. It went through a regeneration cycle yesterday, sitting parked in the driveway. Everything seemed normal after that, moved it over to the backhoe and got the hoses hooked up, and the tractor wouldn't start. Cranks fine, just won't catch and run all the time. If it sits a long time, it'll start, but runs very poorly, then won't restart if tried.

I've replaced both air filters, and also the fuel filter. Bled the air out of the fuel system several times, still no start. I have the owner's manual and the factory service manual, and neither one gives much guidance for a no start situation. Any ideas here to start tracking down the problem?

Here's a video of the instrument cluster during a start attempt. Notice the change in engine sound a few seconds in.

Thanks in advance...

That cranking seems very weak.
You say 12.7 volts, but have you measured actual battery voltage while cranking?

 

[rScotty]

The video is very helpful. I can clearly hear the starter and also the change in engine pitch when compression ignition strats. I agree that the cranking seems oddly weak especially on a tractor measuring 12.7 volts.
Is that cranking speed normal for your M62?

That Makes me wonder if the battery is good but the connection to battery cables are poor. Might as well attend to them - especially the ground side.
Arguing against myself I might say, "does the weakness really matter since it is enough to get the engine to fire?"
But the answer to that is I simply don't know how sensitive the electronics on the new M62s is to voltage drop.... & it costs nothing to clean up the cable connections.

BTW, what color is the exhaust smoke when it is cranking and then does it change when it starts to run?

Also, I'm not sure of the sequence. It sounds like after the regen it started OK - that's good. But then it didn't start after hooking up the backhoe? What are your thoughts on that? Any chance that hookup went wrong and the load on the hydraulics iscausing the low cranking speed?

Finally, when did you change the filters. What drove you to do that. Any chance you changed filters right BEFORE hooking up the hoe and then it didn't start? If so, repeat the bleed sequence over and over and over....

rScotty - confession, I've been a mechanic professionally and then as a hobby for most of my life.

 

[RedNeckGeek]

Yesterday I got a reply from Jennifer Bond on the Youtube page where I posted the video. She has an M62, and had experienced the same problem while attaching the backhoe. It turns out there is a safety switch in the 3-Point/Backhoe valve switches. If the hoses aren't hooked up in backhoe mode, the tractor won't start. And that's exactly what was happening.

This morning I put the levers back in 3PH position with the hoses disconnected, and it started after the 2nd turn of the key. The first was probably filling up the fuel filter I changed. It's back to normal now, and the BH is installed and working, with the levers in BH position.

Just out of curiosity this morning, I got out the "Kubota Backhoe" book, the skinny one that just covers the BT1400. There, on page 21, at the end of the instructions for REMOVING the hoe, under an IMPORTANT heading I found: "After dismounting the backhoe, set the directional valve levers in "3-POINT HITCH POSITION (A)". If not, the tractor will not start."

Sure wish I'd seen that earlier, and that it was included in the instructions for installing the backhoe, too. Now, thanks to Jennifer Bond, I know. Jennifer, thank you SO MUCH!!!!!!!!!!

 

[JenniferKubotaM62]

Woooo hoooo what team work.... We did it buddy!!!!!! Well done!!!

I posted your experience over on orange in case anyone else has this happen.

M62 no start, sounds like thrown rod...

I had an experience recently that scared the hell out of me... I was able to solve it and I noticed that a Youtuber I subscribe to had it happen to him.... and I was able to help him solve it... boy do I feel great..... am so happy for him... if any of you have a no start condition on your M62...

www.orangetractortalks.com

PS: I'm sure I'll be reaching out to you when I put on my 3rd function on the back for a thumb, I see you've done it.

Jen