DF 254 PTO Speed

[Ross71]

The DF254 has two PTO speeds, 540 and 1000. Great, but at what engine rpm? I've looked in the operator manual, I e mailed Dong Feng but can't find the info. I think it is 540 pto rpm at 1500 rpm engine speed(or 1000pto rpm) but does anyone actually know what is the magic number?

Cheers, Ross

 

[RonMar]

The PTO speed is what the output shaft turns with the engine at FULL rated RPM. There should be a mark on your tachometer around 2200-2300 RPM(mine has a green arc in this range. It is also the peak RPM your governor should be set to maintain at the full throttle position. Basically the maximum sustainable HP output RPM... So, need 540 RPM to run the brushhog and mow, or run the chipper? Set the selector lever to the 540 position, push in the clutch and engage the PTO lever. At idle RPM, Slowly let out the clutch to spin up the mower chipper ect. Once the clutch is out/PTO fully engaged, slowly push the throttle lever to full to accelerate the blades to full RPM, and leave the throttle in the full position. If mowing, select the appropriate gear to deliver the desired groundspeed.

Don't think I have ever seen a 1000 RPM PTO impliment. It would probably be best used if driving a PTO water pump(transfer or fire) IF you are just mowing the lawn, you probably do not need full engine HP. but still need 540 RPM for mower blade tip speed. To make things a little less noisy, you can select 1000 PTO RPM on the lever, but only run around 1150 engine RPM which will get you 540 RPM on the PTO shaft at reduced available HP. I do this occasionally when mowing grass on level ground... You MUST use caution when doing this though as overspeeding a 540 RPM impliment such a s a brushhog/shredder, mower or chipper can lead to rapid violent death when it throws a heavy steel blade or the gearbox explodes...

 

[Diamondpilot]

What Ron said is all true but for the health of you engine and gear box It's much wiser to just run it at 540 and the green arch on the tach. If not you are lugging the engine and causing premature wear through stress.

Diesel engines are happy running at max power for long periods of time. Its still a relatively low rpm and does no harm.

Chris

 

[Bob Rooks]

FYI. 1,000 r/m implements will have a 21 spline shaft. This is to keep them separate. The only two speeds that work with a 1-3/8" six-spline shaft are 540 and 720 r/m. However, I'm told that some, but not all, Chinese tractors will have 1,000 r/m PTO output speed in the high range.
On my Yuchai dozer I get 540 r/m PTO speed with the throttle set at 1,850 r/m. Personally, I don't advise running against the governor stop because that's all you will get and no more. No reserve. Best to check it with a photo tach, that's what I did.

 

[cleat]

My DF254 needs the engine to be at 2200 RPM to get 540 PTO. I checked this using a hand held tach.

However, I usually mow at 2000 RPM because I get a good cut with a little less noise at this RPM.

I blow snow at around 1600 - 1800 RPM unless I am into really heavy drifts.

Cleat

 

[Ross71]

Thanks for the replies. My tractor has a green arc on the tacho from 700rpm around to 2500. More than that is red, below 700 is yellow. Apart from the numbers, and those coloured zones there's no other marks(not even the maker's name).

The twin rotor rake I've been using is meant to be run at 540. It seems to be right at about 1650 engine rpm. At 2000 engine rpm the rake was going way too fast.
I think I need to get a hold of a hand tachograph....

Ross

 

[greg_g]

Interesting that there's no mark on the tach to indicate PTO revs. If the tines are spinning too fast at 2000 rpm, you may inadvertently have the PTO speed select lever in the wrong position. Rather than the desired 540, you could be in the 1000 (possibly 720) position.

//greg//

 

[jimogeek]

Mine is the same way, have a 2006 foton 250. No green band and the sticker was missing from the 540/1000 selector lever. Figured it out pretty quick though, no way I could cut grass at 1000 rpm but I may have gotten a finish mower just a bit larger than I should have anyway (72" king cutter finish mower).

 

[Ross71]

Interesting that there's no mark on the tach to indicate PTO revs. If the tines are spinning too fast at 2000 rpm, you may inadvertently have the PTO speed select lever in the wrong position. Rather than the desired 540, you could be in the 1000 (possibly 720) position.

//greg//

I read this, and thought, "actually I can't remember why I put the lever forward"

The knob on the top is marked for 540 and 1000, but turns freely. Anyhow, I went and checked. I have been using the correct setting -thank the lord, I think I'd die of shame if I'd been getting it wrong all this time.

I've been running a flail topper this morning. 2200 on the tacho and the topper seems fine, so I guess that 2200 is correct, as everyone says.

So am I wrong running rakes and tedders at lower rpm. They don't seem too happy running fast, or is it my lack of nerve?

 

[greg_g]

Implement manufacturers optimize design efficiency relative to a specific number of PTO revs: 540/720/1000. The vast majority of PTO implements sold for this class tractor in America seem to be 540. Not that you cant find the occasional 720 or 1000 implement. Its a simple matter of trusting the manufacturer to specify the correct speed

//greg//