PTO rpm's

[budepps3760]

I am new to owning a tractor and would like to ask the experienced folks what is the best practices in bush hogging. I have a Mahindra 2810 with about 28hp on the pto. When bush hogging should I keep the rpm's at 540 while mowing cleared fields or is it better to run the engine/pto at lower rpm's at a lower level? I don't know if it puts more strain on the engine and related parts by running at a rate that is more than required to do the job or if running at lower rpm's actually causes more strain on components. It's a 2000 year model however it only had 430 hours on it when I purchased it. Thanks for any suggestions,

 

[prosperity]

For any implement like a bush hog, always run at rated RPM for 540.

The bush hog will cut better with the blades running at rated speed.
Your tractor cooling system will work the way it was designed to.
If you tractor has an HST transmission it will run cooler and not strain.

In my opinion, running any PTO implement at less than rated speed is harder on the tractor and implement.

 

[bilrus61]

Not sure I agree on running it at PTO speed. My M7040 PTO speed is 2150 RPM. I usually run it about 2000 RPM. This gives me around 515 to 520 on my implement PTO. My mower is a 8 foot so it is well under the HP for that tractor and it's pretty new so the blades are about as sharp as a cutter is going to need to be. Leaves a great cut, tractor runs cool and quiet, doesn't lug, and I don't see any disadvantages in doing that. Now if it was a hydro tractor I would be concerned with the cooling fans not cooling the hydro fluid if I was running it extended hours at lower RPM. But as far as the implement goes, if it's doing its job at 510 RPM and its rated 540 I don't think your hurting it in the least. A post hole digger is "rated" at 540 RPM and I would NEVER run one like that. I put the tractor on high idle to dig a hole. Use your ears, if things sound fine they very likly are, if something seems to be struggling,lugging, not cutting clean, then goose up the RPM till it does.

 

[Ted Summey]

With 28 hp at the PTO you will likely need higher PTO speed to take care of thick stuff. Even thick fescue or other grass can bog a small tractor down. Plus with sharp blades and the higher blade speed you will get a smoother neater cut. Higher PTO speeds can also allow greater ground speed and shorten the time to complete the job in lighter brush.

Bilrus61 has a much larger tractor and the inertia of an 8 foot shredder or mower will overcome any bogging presented by lighter grasses and weeds.

 

[Jarrod32]

For any implement like a bush hog, always run at rated RPM for 540.

The bush hog will cut better with the blades running at rated speed.
Your tractor cooling system will work the way it was designed to.
If you tractor has an HST transmission it will run cooler and not strain.

In my opinion, running any PTO implement at less than rated speed is harder on the tractor and implement.

Agree with everything above. The implements are designed for optimum performance at the rated PTO speed. So everything above goes for running it faster than rated PTO speed, as well as slower. Harder on tractor and implement. The cutter is designed to run at 540. Anything above rated speed will be much harder on the gear box and other moving parts, and will likely shorten the life of the implement.

 

[GManBart]

With 28 hp at the PTO you will likely need higher PTO speed to take care of thick stuff. Even thick fescue or other grass can bog a small tractor down. Plus with sharp blades and the higher blade speed you will get a smoother neater cut. Higher PTO speeds can also allow greater ground speed and shorten the time to complete the job in lighter brush.

If you size the cutter to the available PTO power, none of this is true.

 

[Ted Summey]

Never argue with an idiot. They will drag you down to their level, and beat you with experience!

This IS TRUE. No argument from me.

 

[Reverser]

Use your ears, if things sound fine they very likely are, if something seems to be struggling, lugging, not cutting clean, then goose up the RPM till it does.

+1
Words of wisdom.

 

[sfabern]

I mow a field with a 33HP Kubota and a New Holland 918L flail mower. If the grass gets tall (2-3 feet) I find it difficult to cut it evenly, with heavy fescue (I think) clumps not cutting. I am using the Kubota recommended PTO speed and moving slowly(very) when in the heavy stuff, but still some clumps will be rolled over and not cut. The mower is not laboring, nor is the belt slipping (I am listening all the time). I am wondering if the knives need to be sharpened. I used a "hammer knife" with an Ford 8N as a kid, and I don't remember the knives needing to be particularly sharp. Any ideas will be welcomed.

 

[SPYDERLK]

More to implements than just cutters. All have different needs.