JD X749 Diesel keeps dying out while cutting.

[Mike VS]

Hi guys, Kinda new here so bare with me...
I have a JD X749 - 4 wheel steer/ 4 wheel drive diesel powered mower that is the best thing since sliced bread! I have had it for over a year and put near 50 hours on it with zero problems.
Now I do... While mowing today it suddenly died from full RPM. It did the same thing last month at which time I freaked out and parked it while I pondered the problem. At that time I tried restarting it after a 1/2 hour and it immediately fired up and continued running until today. This time when it died I gave some quick testing to discount possible problems. When it died I immediately tried restarting... Yup, fired right up and continued cutting for 2 minutes until it started dying again. This time I disengaged the PTO (cutting deck) to see if there was any load problem. Nope, just finished dying out without any effect. Again it restarted right back up and soon died again in a few minutes. I tried to throttle back while disengaging the PTO again. Zero effect as it just petered out from full RPM. This time I stopped, opened the hood and checked the obvious; Oil good, coolant good, temp very good running with gauge at 50% mark, air cleaner good, all hood breather screens clear. Fuel level above 75%, Nothing found at all, but there was a bigger gap this time before restarting it (just like last month). Again it fired right up with no hesitation and continued cutting until I finished 15 minutes later.
I know gas engines pretty good but I'm new to diesels. It acted like it lost spark but that obviously is not the case. There seems to be a correlation to the amount of off time before restarting. I did the maintenance about 20 hours ago changing the oil, fuel and air filters. Also the seat cut out switch has been disabled so I don't think it's that.
I'm wide open to suggestions if anybody has any guesses. Thanks

 

[Richard001]

Mike,

I just checked with Tractor Data and I got this: 2008 - 2012 Select X700 Series

So I am wondering, are you the first owner, if so, how is it that the last X794 was made in 2012 and you are saying that you have had this tractor for about a year.

Richard

 

[Mike VS]

Correct Richard, I bought it used a year ago.

 

[Richard001]

I did the maintenance about 20 hours ago changing the oil, fuel and air filters. Also the seat cut out switch has been disabled so I don't think it's that.

So lets see if I understand this correctly. The tractor worked fine last year and now, after you did some service on the tractor, it's acting up.

Is it possible that something you did during the service is causing this problem?

Think back about what you did and what you removed and/or replaced. Perhaps something didn't get put together properly.

Richard

 

[Mike VS]

No problems after service. I did that 20 hours ago... that is about 6 months and 10 cuts ago.

 

[zzvyb6]

Safety (seat, pto, parking brake) systems, fuel supply, temperature.

 

[Deere Dude]

I have a X740 so fix might not be the same as yours. My mower would continue to shut off and found the screen before the radiator was plugged a little bit but the oil cooler before the radiator was plugged and the radiator behind the oil cooler was plugged also. The temp was warm but not in the red zone.

 

[Mike VS]

Ok, when you say plugged do you mean the fins were filled with debris? My temp has been on the low side all along, and today was even lower due to the cool temps. I will check it anyway tomorrow. Did it die suddenly or slowly cough to a halt?

 

[Mike VS]

"Safety (seat, pto, parking brake) systems, fuel supply, temperature."

Of all those, it seems mostly like temp by the way it will restart every time. But it looks and feels cool as a cucumber. I'll be checking that more closely.

 

[ruffdog]

I've got a x744 and my dad has a x749. Have you ever pulled the side panels and the radiator screen (LH side) and cleared out the debris? Take a air wand and blow from the engine side of the radiator to clear the dirt from the fins. stick a light on the rear side and use a mirror on the front side to SEE if the radiator is really clear. You should be able to SEE through.