B2620 MMM RPM

josolar · Jul 12, 2013

What should I run the rpm's at on my B2620 while running a 60inch Mid mower? The dealer said 2500 rpm, slightly lower then what the rear Pto calls for.

kcender · Jul 12, 2013

I run around 2500-2600 with my 54 inch deck.

oldballs · Jul 12, 2013

I run mine ( MMM 60 inch deck) at 2600 - 2800 rpm, but may go check the manual.

Finnster · Jul 12, 2013

Ive been running at 2500 and satisfied on the performance.

Maestro71 · Jul 14, 2013

The manual says full throttle

oldballs · Jul 14, 2013

Maestro71 said:
The manual says full throttle

Yeah, mine reads the same now that i checked it. But I don't mow at full throttle because it doesn't seem necessary to me.

Maestro71 · Jul 17, 2013

So it's ok to run lower rpms? I just recently started using my mmm and am not a big fan of it so far. Still trying to figure out my yard with it. I just read a post about adjusting the dck for the best performance so that's next. I would rather not run at full throttle if its not a Problem.

josolar · Jul 18, 2013

Based on the sound of the engine and mower, 2600rpms seems about right. Its what the dealer recommended, uses less gas, and works well. Full throttle seems a bit much. Of course it is important to lower the throttle all the way down before engage/disengaging the PTO.

powerstroke444e · Jul 18, 2013

oldballs said:
Yeah, mine reads the same now that i checked it. But I don't mow at full throttle because it doesn't seem necessary to me.

Thus the reason I like buying new machines, because you don't know how the pervious owner treated them.
Reason to run them wide open is the cooling system works better you don't lug the engine which creates more heat and the hydro don't get burned up from lack of cooling or oil flow.
I have 15+ machines and all are always ran at wide open or rated rpm farm tractors, mowers and trenchers some have over 8,000hrs some are near new with no adverse effects from running wide open.

Finnster · Jul 18, 2013

powerstroke444e said:
Thus the reason I like buying new machines, because you don't know how the pervious owner treated them.
Reason to run them wide open is the cooling system works better you don't lug the engine which creates more heat and the hydro don't get burned up from lack of cooling or oil flow.
I have 15+ machines and all are always ran at wide open or rated rpm farm tractors, mowers and trenchers some have over 8,000hrs some are near new with no adverse effects from running wide open.

I'll have to try it and see how it goes. Can't say mowing has been much of a stress as opposed to some of the other chores like box blading or hauling a big load in the FEL. But if it doesn't hurt and maybe I'll mow a bit faster why not?

Would help get the blade speed up a bit. That's a big plus.

BrierPatch · Jul 18, 2013

powerstroke444e said:
Thus the reason I like buying new machines, because you don't know how the pervious owner treated them.
Reason to run them wide open is the cooling system works better you don't lug the engine which creates more heat and the hydro don't get burned up from lack of cooling or oil flow.
I have 15+ machines and all are always ran at wide open or rated rpm farm tractors, mowers and trenchers some have over 8,000hrs some are near new with no adverse effects from running wide open.

I'm curious, do you drive your vehicles in low gear with your foot to floor on the accelerator to make them run cooler and last longer? This might be the reason I buy new instead of used!

powerstroke444e · Jul 18, 2013

BrierPatch said:
I'm curious, do you drive your vehicles in low gear with your foot to floor on the accelerator to make them run cooler and last longer? This might be the reason I buy new instead of used!

Everything is built to for a use, vehicles are not able to operate wide open, max load max HP for extended periods of time as there cooling systems cannot handle that.
Ie most new 1/2 tons can pull 10,000+ but they will destroy themselves if you did that for 300,000 miles thus the reason most business use buy right tool for the job.
Almost every brand of equipment is rated to run wide open and at rated horsepower for extend periods. Slow down the engine and the will over heat if you add much of a load. Not to say that I run the posthole digger or unloading auger wide open. But for mowing or ground engaging tasks wide open.
To answer you do I run mine wide open in low only when I need to and when I am done most of my vehicles are only worth what they weight.

josolar · Jul 18, 2013

powerstroke444e said:
Thus the reason I like buying new machines, because you don't know how the pervious owner treated them.
Reason to run them wide open is the cooling system works better you don't lug the engine which creates more heat and the hydro don't get burned up from lack of cooling or oil flow.
I have 15+ machines and all are always ran at wide open or rated rpm farm tractors, mowers and trenchers some have over 8,000hrs some are near new with no adverse effects from running wide open.

Dealer advised to run at 2,600rpm's, just below the 540 pto mark. Not too mention you are not supposed to run the tractor at full throttle during breaking hours.

WilliamBos · Jul 18, 2013

josolar said:
Dealer advised to run at 2,600rpm's, just below the 540 pto mark. Not too mention you are not supposed to run the tractor at full throttle during breaking hours.

The machine needs to be worked on break in, not babied!!

Like posted above, maximum efficiency is achieved at recommended RPM's!!

oldballs · Jul 18, 2013

Since we are on the subject of MMM rpm and clutch, what do you all do when you have to cross a gravel road or some other obstacle? Obviously, if it was a long stretch I raise and disengage the mower completely. But for short stretches where you don't want to throw some gravel or road dust, I just push the clutch in. However, I do not throttle down. Then I just let the clutch out real slowly as I resume.

Finnster · Jul 18, 2013

powerstroke444e said:
Everything is built to for a use, vehicles are not able to operate wide open, max load max HP for extended periods of time as there cooling systems cannot handle that.
Ie most new 1/2 tons can pull 10,000+ but they will destroy themselves if you did that for 300,000 miles thus the reason most business use buy right tool for the job.
Almost every brand of equipment is rated to run wide open and at rated horsepower for extend periods. Slow down the engine and the will over heat if you add much of a load. Not to say that I run the posthole digger or unloading auger wide open. But for mowing or ground engaging tasks wide open.
To answer you do I run mine wide open in low only when I need to and when I am done most of my vehicles are only worth what they weight.

Have you had overheating issues while mowing? It has yet to move from the normal operating range on mine (rpms are @ the PTO mark to clarify)

Maestro71 · Jul 18, 2013

Is it not good to run full throttle in low gear? The manual says full throttle when using the mmm so that's what I've been doing. I would never take the dealers word over the manual. Not my dealer anyway.

josolar · Jul 19, 2013

Mower manual says to run at full throttle. Tractor manual says to run mid pto level or 2600 rpms. Personally for flat mowing flat mowing I run 2600-2700 rpms, mowing hills that require transmission power to climb I throttle up a little bit.

BrierPatch · Jul 20, 2013

powerstroke444e said:
Everything is built to for a use, vehicles are not able to operate wide open, max load max HP for extended periods of time as there cooling systems cannot handle that.
Ie most new 1/2 tons can pull 10,000+ but they will destroy themselves if you did that for 300,000 miles thus the reason most business use buy right tool for the job.
Almost every brand of equipment is rated to run wide open and at rated horsepower for extend periods. Slow down the engine and the will over heat if you add much of a load. Not to say that I run the posthole digger or unloading auger wide open. But for mowing or ground engaging tasks wide open.
To answer you do I run mine wide open in low only when I need to and when I am done most of my vehicles are only worth what they weight.

WilliamBos said:
The machine needs to be worked on break in, not babied!!

Like posted above, maximum efficiency is achieved at recommended RPM's!!

I'm not trying to badger anyone nor am I trying to pick arguments, but I just want to give another perspective. I think there is a little too much emphasis being put on cooling system design and rpm overheating. I beleive there is a happy medium between running wide open and lugging an engine. I don't think running the engine at 2500 rpm could even be close to considered lugging the engine while mowing, heck 2000 rpm isn't either. I probably run mine about 2400, but it's more about blade speed than engine loading or effenciency. I have never had any issues with any of my equipment overheating when not running wide open. My old Kubota was only rated at 17 hp and it ran a 60in deck just fine so I really don't see how my newer 26hp needs to run wide open to accomlish the same task or would be considered lugging the engine if not running wide open nor is it going to overheat by not running wide open. As far as effenciency, I don't think it's maximum effenciency to run an engine at wide open full power when only using maybe 25% of it's power. I think the recommended mower rpm is more about blade speed, which has already been mentioned. So, I think I will take my chances and not run my mower wide open for mowing. Thank goodness they put a throttle on these machines, I think I will use it. The good thing about this is that everyone can run their tractor the way they want to and hope for the best, but in reality these kubotas will run for a very long time no matter how you run it (within reason of course). :thumbsup: Just my :2cents: