RPM questions (nothing in the manual)

[xring100]

I normally set throttle at about 1500 for loader work And use foot throttle from there. 2600 for top speed. I have a gear Trans.

 

[Deano]

Whatever your load dictates.

 

[ritschner]

I have the older version of your tractor. Typical rpm for loader or blade work that I use is 2000-2200 rpm. When mowing with the brush hog I set to run at the top of the 540 PTO band since that maintains it in the band when mowing. Typical commute around the property rpm is 1600-1800. Of course this is after warm up.

 

[94BULLITT]

PTO speed for PTO work (the red mark on tach)

The few hydro tractors I have been around perform good a 2000-2200 for grading or loader work but you may need to increase RPM's at times.

 

[sandyc]

I run my 2620 at the lowest rpm to get the job done for FEL and BH work. For blowing snow it is wot.

 

[Tractor Seabee]

My BX 25 shop manual states that 540 RPM PTO is obtained at max throttle. I run it around 2200 most of the time for general work. Speed ut when digging stumps with BH or running RT or Bush Hog. The BH and RT work better at maqx. I match speed to load. The small bota's are designed to run at max RPM all the time. With a new one you can get max HYD pressure at about 2300 as the pump is not bypassing anything and the relief valve maintains steady pressure.. GPM (speed of cylinder response) requires more throttle unless you like to go slow like I do. As the pump wears the relief valve will work less until the pump drops to less than design pressure. I added shims and raised the HYD to 2000 PSI and it sure made a difference.
Ron

 

[joshuabardwell]

That "540" mark is telling you what engine RPM will produce 540 RPM at the PTO. PTO-driven implements are usually designed to run at around 540 rpm, so when running a PTO-driven implement, you'd want to set it near to that RPM and keep it there. Some folks will run the RPMs a little lower to slow the implement down, and that's okay, as long as the implement still performs acceptably. For example, with a finish mower, you're going to want a certain minimum blade speed to get a decent cut.

You don't have to worry about running the engine at that speed. A tractor engine should be designed to run at PTO speed day in and day out for the life of the tractor. It's not like your car where if you ran it at the redline all the time, you'd burn out the engine. So don't worry about babying the tractor. It can take it. But if you're like me, sometimes you'd like a little more peace and quiet, so you turn the engine down some. That's okay, but look for signs of inadequate RPM, like the engine bogging down, lugging, or smoking.

I don't think you say whether you have an HST or a gear, but if you have an HST, it will respond better to higher RPMs than lower. In general, whenever I'm doing much other than driving unladen on flat ground, I am running at PTO speed, to give me maximum ground speed at a given gear. If you press the HST pedal down and the RPMs drop, the tractor slows down or stops, and you hear the wining that indicates the transmission is going into relief, that means you need to either: back off the pedal, increase RPMs, or shift to a lower gear. Or some combination of those three.

 

[Gale Hawkins]

Rule of Thumb: 540 PTO RPM mark is perfect.

Like joshuabardwell stated it was designed to work at that RPM range 24/7/365.

I noticed the late FIL had set max throttle to equal 1700 RPM which is the 540 mark on the 1976 265 MF. I have thought about resetting it but with kids about to start to bush hog with it I may leave it where it is at because when as a kid my BIL drove it.

 

[wcampbell47]

For front loader work I run my B3200 at 1800 to 2000 RPM's. The loader gets jerky around 2000. The hydro trans seems happier at the higher RPM's as well. I read somewhere that the higher the RPM's the better the hydro likes it. For PTO I go to 2200 if the grass is light, all the way to the 540 tick for heavy grass.

 

[Redneck in training]

The engine has the lowest specific fuel consumption and highest torque at around PTO speed mark. When cutting grass or working hard PTO speed will deliver the best performance. Google engine chart for your Kubota engine and you will see that the PTO speed is little past maximum torque. The reason being if you load the engine that rpm will start to decrease the torque starts rising to some degree and therefore it is harder to bog down the engine. For the light or fine work you might select lower rpm but I would stay above 1500 -1600 rpm. For most work stay above 2000 rpm.