Truth in Recommended HP Required

[Dirtandgrass]

As a first time tractor buyer, the deeper I get into this "research project" the more questions I keep running into. I tell you what...before diving in, I would have NEVER guessed it would take this much information to be an "informed" buyer. But, nevertheless...

I have just about gotten all the details nailed down. In terms of price I have been pitting two local dealers against each other to get the best price. So, What I am looking at is (as you all know by now I am sure) the M7040. The rotary cutter is the 7 foot heavy duty Rhino. I called the dealer today to verify the model number on the cutter and he told me the TW84 lift type.

So my question is this: The Rhino website shows the min HP required for that cutter as 60. The 7040 has 62 HP at the PTO. Since the Rhino recommends 60 HP am I going to be "cuttting it close" (no pun inteded) with a 62 HP PTO tractor? The dealer says it will be fine...but he is trying to get into my pocket. I don't want to be using this cutter if its going to be a constant strain on this tractor. What do you all think? I just hesitate a little bit with the whole 62 HP available and 60 MIN required. MIN being the key in that statement.

Also, just an FYI the price I am getting on the tractor itself is just under 30K for the M7040 Hyd Shuttle, one rear remote, LA1153 loader with self-leveling valve. All the other stuff is the standard stuff on the 7040, like 30 inch R1 tires, steel wheels (not cast iron and not filled) etc etc.

Regards,

Tractor Academic

 

[jbrumberg]

Dirtandgrass:

There have been many threads/posts on TBN about the maximum and minimum requirements comparing PTO HP to rotary cutter size. I believe your 62 HP's will adequately power the 72" HD rotary cutter. I would be more concerned if the PTO HP exceeded the maximum HP parameters for the rotary cutter. The common "Rule of Thumb" is 1 foot of cutter for every 5 HP. Jay

 

[CumminsLuke]

You'll be fine with that combo. I am really surprised Rhino calls for that much HP on a 7' cutter. Three weeks ago I pulled a BushHog 3615 Legend with my 7040 to trim up 40 acres of pasture and I pulled it with no problem. The 3615 is a big hoss of 15' flex-wing cutter that most people put on a 100-150 hp tractor.

 

[JiminGa]

I used a Ford 3000 to pull a 6ft bushhog for many years with no problems. I believe that tractor is rated at about 45 hp. I would think a 62 hp machine could pull a 8 ft cutter easily.

 

[thunderworks]

My L5030 pulls a medium duty 7' Bushog with no trouble. My tractor has approximately 42hp at the pto.

 

[SDT]

D&G:

The 7040 should have no problem with a 7' cutter unless you get into very heavy grass, e.g., brome grass that is laying down, and try to cut it too fast.

That said, 7 foot cutters are not ideal for several reasons. Generally, they pull harder (require more HP) than 8 foot, dual spindle cutters. More importantly, a 7 foot cutter is very long and places lots of mass far from the lift arms. Since you will have a FEL installed, front end weight should not be an issue even if not FWA.

SDT

 

[Mickey_Fx]

With equipment like this I think mfgrs are assuming a certain amount of load due to grass density underbrush, etc. plus their machine design. Same can be said for responses to questions like this. Different mowers and differing field loads result in differing power needs.

I use this example on occassions to demonstrate my thoughts. Before buying my tractor I used to use my BIL's tractor and mower. His tractor is a 30 HP model and older 5' or 6' JD model. That set-up had a real hard time in a lot of places in the pasture, all grass, no saplings. Now with the Yanmar, 24pto HP and 5' mower, my machine doesn't work very hard in most places in the pasture and can handle the densor parts without over loading the tractor. 2 setups on same field and noticable differences in how the tractor handles the task. The old JD desing doesn't clear out the cut grass as well as my mower thus big diff in power requirements.

Just my opinion on why it hard to provide a generic answer to how much power is needed.

 

[N80]

I started out with an old, heavy duty (looking), single spindle John Deere pull type rotary cutter with my L4400 which gets around 40 hp to the pto. I had no problems with any of the mowing that I did. However, it was primarily grass, brush, briars and saplings. No trees.

My B-I-L told me it would cut anything I could run over with the tractor. I never tackled that sort of stuff and I suspect if I did, 40 hp would not be enough.

I think your 7040 will handle that mower without any problems at all. (But if you are going to knock down big stuff....wear your ear plugs!)

 

[Soundguy]

Is that a single spindle 7' mower.. or a dual spindle mower? The single spindles take a bit more 'umph' to get going... In any case.. you have it in black and white.. min is 60.. you have 62.. that technically makes you 'PASS' the go/no go test.

Here's some comparison... I have a 1975 ford 5000.. 70eng hp.. 67 pto hp... I run a 10' 3pt dual spindle mower behind it in anything I can get the front axle over.. brush.. weeds.. grass.. occasional accidental 2" woody and 3" green material ( oops! ).. never had a problem.. 3' tall lush grass will give it a run for it's money though.. and I have to use a low gear. normall I run in 5/High to mow.. but use 4/low for heavy stuff.. and if it's 7' tall jungle.. 3/low just because i can't see in front of me.. not because i need the slower gear..

Soundguy

So my question is this: The Rhino website shows the min HP required for that cutter as 60. The 7040 has 62 HP at the PTO. Since the Rhino recommends 60 HP am I going to be "cuttting it close" (no pun inteded) with a 62 HP PTO tractor? The dealer says it will be fine...but he is trying to get into my pocket. I don't want to be using this cutter if its going to be a constant strain on this tractor. What do you all think? I just hesitate a little bit with the whole 62 HP available and 60 MIN required. MIN being the key in that statement.

Also, just an FYI the price I am getting on the tractor itself is just under 30K for the M7040 Hyd Shuttle, one rear remote, LA1153 loader with self-leveling valve. All the other stuff is the standard stuff on the 7040, like 30 inch R1 tires, steel wheels (not cast iron and not filled) etc etc.

Regards,

Tractor Academic

 

[L4400]

I recently purchased a Kubota L4400 and traded in a L2500. The L2500 I think had 24 pto hp. I have a 36" leaf blower I use that requires 35 pto hp. When using the leaf blower with the L2500, I couldn't get to the end of my driveway and the temperature gauge would be pegged. I had to stop about every 10 minutes to let it cool down. The L4400 is rated at 37.5 pto hp. This was one of the things I was considering when I bought the L4400. I can blow leaves for hours with the L4400 and the temperature gauge isn't too far past the cold part of the temperature gauge. Actually, I thought the temp. gauge wasn't working and popped the hood and could touch the muffler and engine (only for a seecond). It was hot, but what the gauge was showing was accurate. With this, I wonder if the implement companies are rating their implements as if it's a gas powered tractor, I don't know. The leaf blower is the biggest hp drawing implement I have and the L4400 handles it with ease.