What RPM's do you use

[leoric]

I have a b2650 and I was poking around the internet the other day looking for what rpm range is used for mowing/FEL work. I grew up around old farmers and they always taught me to use their equipment at the lowest RPM needed to get the job done. I feel like this isn't true anymore. I was mowing around ~1800 rpms and doing loader work around ~1200. I found on other forums people said to run it above 2k most of the time when in use. I did look at the manual and the mowing rpms say ~2500 so I've since changed that.

Can I get some opinions from you guys?

 

[shootem604]

With PTO driven equipment you should run your RPMs to the level required to produce the desired PTO speed. If your tractor produces 540 PTO RPM at (for example) 2200 engine RPM, that's what I would do.

 

[85Hokie]

Running an engine at a lower rpm does NOTHING good for the engine - this is a concept of people thinking that babying the engine is the best, far from it! An engine is designed to RUN at "X" rpm....that is where it makes the correct HP and or Torque......

As mentioned - most tractors have a very specific 540 rpm via engine rpm - and that should be followed.

While many farmers may run at lowest, most commercial operators will not - they will run it up to where they have the most GPH flow rate with their hydraulics.

Now the flip side of this...run the living snot out of it, well not a bad thing, most of us do not run it all the way up......I have had to, on few occasions to get that little extra umph.....but to answer your question - I run mine at about 90% WOT 90% of the time!

Cutting grass - I find that I am 90% to 95% WOT
Sometime with HOE work - I will back the throttle back a bit.....why? Due to being in a very tight area, and the swing is a little aggressive on the BX25D

 

[dirtydeed]

Obviously, for pto work whatever is necessary for 540 pto rpm (I tend to run it just a bit slower). All else, I only run what is needed to do the job. I rarely run WOT unless I need the extra power for the demand. Most loader work, I'm at roughly 1500 rpms, a bit higher for BH to get some speed.

Ran my BX23 the same way. Had it for 12 years with no engine or transmission issues...for many, many, many hours.

I see lots of youtube video's where people are running full bore to do very light loader work...makes me cringe. I'll keep doing what I've been doing in the past. It has served me well.

 

[GeoHorn]

Higher RPMs are not as harmful as the "old timers" imagined. When an engine runs at higher RPMs it actually keeps a film of lubricant better distributed resulting in less wear...AND... there are fewer areas of temperature extremes those parts have to move against...again, resulting is less wear than lower speeds which can cause "lugging", a loss of momentum within the engine resulting in contact-wear.


Read your Owners/Operators manual and run it at rated PTO speed. You'll get a better cut, your attachment will also be better lubricated, and your equipment will generally perform better all-around.

 

[Freeheeler]

I'm no expert, so don't do as I do. I'm just saying what I do and why, hoping the experts can chime in give some advise. I don't do any PTO work, just loader and backhoe which is all hydraulic. I don't run WOT, I run it at whatever rpm it takes to make it sound like it's not bogging down. Usually anywhere from 1500 to 2300 depending on how hard the task is. My understanding is that bogging down a diesel is very hard on it, but WOT isn't needed either. For hydraulic work, WOT makes for fast jerky controls, slow rpm makes for smooth slow work, I like it somewhere in the middle.

 

[dirtydeed]

I'm no expert, so don't do as I do. I'm just saying what I do and why, hoping the experts can chime in give some advise. I don't do any PTO work, just loader and backhoe which is all hydraulic. I don't run WOT, I run it at whatever rpm it takes to make it sound like it's not bogging down. Usually anywhere from 1500 to 2300 depending on how hard the task is. My understanding is that bogging down a diesel is very hard on it, but WOT isn't needed either. For hydraulic work, WOT makes for fast jerky controls, slow rpm makes for smooth slow work, I like it somewhere in the middle.

Well said.

I do wish that an auto-throttle was available for the B series. I would've selected that checkbox when I ordered my machine.

 

[leoric]

I'm no expert, so don't do as I do. I'm just saying what I do and why, hoping the experts can chime in give some advise. I don't do any PTO work, just loader and backhoe which is all hydraulic. I don't run WOT, I run it at whatever rpm it takes to make it sound like it's not bogging down. Usually anywhere from 1500 to 2300 depending on how hard the task is. My understanding is that bogging down a diesel is very hard on it, but WOT isn't needed either. For hydraulic work, WOT makes for fast jerky controls, slow rpm makes for smooth slow work, I like it somewhere in the middle.

This is basically what I do as well. Sounds like I'm not far off from others. I just need to make sure I'm not lugging the engine which I was a culprit of before doing some research.

 

[leoric]

Well said.

I do wish that an auto-throttle was available for the B series. I would've selected that checkbox when I ordered my machine.

Only thing I wouldn't like is that just adds more things to break!

 

[chim]

Whe using the FEL, I run the engine at whatever speed is comfortable. WOT exaggerates movements.

With the RFM, the engine speed is determined by observing the discharge of the clippings to have them flow evenly. The grass has a different consistency at different times of the season or wet vs. dry weather patterns.

 

[troverman]

For all my PTO applications, I'm at wide open throttle. For loader work, plowing, or just driving around...part throttle, whatever feels good. I like a nice responsive loader, and that usually means towards the higher end of the RPM scale.

 

[GeoHorn]

Higher RPMs are not as harmful as the "old timers" imagined. When an engine runs at higher RPMs it actually keeps a film of lubricant better distributed resulting in less wear...AND... there are fewer areas of temperature extremes those parts have to move against...again, resulting is less wear than lower speeds which can cause "lugging", a loss of momentum within the engine resulting in contact-wear.


Read your Owners/Operators manual and run it at rated PTO speed. You'll get a better cut, your attachment will also be better lubricated, and your equipment will generally perform better all-around.

I hope it's obvious my previous comments were applicable to PTO driven implements. Loader work is quite different, and I use my foot throttle typically when working with the FEL. If I use the hand-throttle during loader work I typically run it at 1100-1500 RPM which keeps the hydraulics responsive without unnecessary noise and fuel consumption.

 

[Stmar]

I was brush hogging yesterday, rear PTO 520 rpms which put the engine rpms at around 2200. Plowing snow or grading driveway I stay around 2000. I think I read where the mid pto is close to the engine rpm but I never use that.

 

[bearskinner]

Using the front mounted snow blower dawn 1400’ of driveway, it loves to run at 2600, and clears the snow 30 plus feet away. That’s barely using the accelerator pedal, just going along nice and easy

 

[ad356]

i was just thinking about asking this question when i was mowing today. i run my newly acquired BX2350 at 2,400 rpm when mowing. it seems very happy there. i think full throttle is something like 3,200-3,400 which seems way excessive for a diesel engine. i hear occasional reports of kubota diesel engine failure, could be lack of maintenance or it could be excessive wide open throttle RPMS. i was looking at massey GC1705's before i bought my kubota. i think i remember their full throttle RPM being lower. i drive milk tanker (tractor trailer) for a living. 3,200 RPM seems excessive for a diesel unless it was an old screaming jimmy 2 stroke. im not saying to lug it around at 1,600 rpm but i think north of 3,000 is excessive and bad for engine life.

 

[troverman]

i was just thinking about asking this question when i was mowing today. i run my newly acquired BX2350 at 2,400 rpm when mowing. it seems very happy there. i think full throttle is something like 3,200-3,400 which seems way excessive for a diesel engine. i hear occasional reports of kubota diesel engine failure, could be lack of maintenance or it could be excessive wide open throttle RPMS. i was looking at massey GC1705's before i bought my kubota. i think i remember their full throttle RPM being lower. i drive milk tanker (tractor trailer) for a living. 3,200 RPM seems excessive for a diesel unless it was an old screaming jimmy 2 stroke. im not saying to lug it around at 1,600 rpm but i think north of 3,000 is excessive and bad for engine life.

I think you'll find no modern engine can be revved to the point where engine damage will occur. You'll also find that, generally speaking, the larger the engine, the lower the RPM for peak horsepower and torque. I had a 2013 Kubota B2920 with a 1.3L inline-3 engine. Rated PTO horsepower was at 2800RPM; however the engine would rev to maybe 3300 or 3400 RPM. I used this machine for 600 hours, nearly all of it spent operating a flail mower in tall field grass. I would say at least 500 hours were at 3300RPM or as wide open as the throttle would go. The machine never had a hiccup and I traded it in good running condition.

 

[1ruralmailman]

I believe that a service tech posted on here awhile ago that driving the tractor below 2k rpms wasn't good for the hydro transmission. So I run at or slightly above that whenever I'm moving. He stated that was where the tyranny was designed to be run anything lower than that didn't give adequate flow rate to protect the insides.

 

[GeoHorn]

I believe that a service tech posted on here awhile ago that driving the tractor below 2k rpms wasn't good for the hydro transmission. So I run at or slightly above that whenever I'm moving. He stated that was where the tyranny was designed to be run anything lower than that didn't give adequate flow rate to protect the insides.

That likely has merit. I have a couple of hydrostatic-transmission machines and they ALL warn against running to low RPM as it causes overheating of the HST oil.