Going Above Rated PTO Horsepower

[mjp1966]

I have a B1750HST, 20 HP, 15 at the PTO. Been searching around for a good finish mower forever and through a friend of a friends, found a Bush Hog RDTH 72". The mower is like brand new and I think I got a deal at $400. Anyway, in all the rush I never bothered to look up the mower specs. Bush Hog recommends 20+ HP at the PTO. Have to admit, I'm a little green when it comes to this. Should I even bother with this mower or sell it and start the search over? Will it put to much strain on my machine if I run it? I live in Florida, so my property is flat as can be, no hills to mow. Will it be ok? I appreciate any input, thanks.

 

[mendonsy]

You should be fine as long as you stay out of the deep grass. Cutting a 72" wide swath of heavy wet grass takes some power, but if you keep up with it 15 hp should be enough. If the grass gets ahead of you, you can always set the height up a bit for one pass then go back to normal height with a second pass.

 

[skeets]

To be honest Im thinking a 72 incher is a bit much for that little beasty, more like a 60 would work better,, though maybe if you take it slow and steady it would work but 15hp on a 72 incher I think is just a tad on the big side,, ,just MHO

 

[Kingcreek]

I believe 15 at the PTO is going to leave you underpowered with a 72" deck.

 

[76_Bronco]

Let me know how it works out for you because I'm picking up a Land Pride FDR2572 6' grooming mower later on this week. I got it at a good deal also, it was too hard to pass up at $400. So if it doesn't work out I can always sell it for a profit, but it sure would shorten my mowing time if my tractor can handle it.

 

[Paulemar]

It's considered a bit big for your tractor but should be OK if you keep that fact in mind. The weight on your 3 point may require some extra weight out front if you are going to be lifting it much. The flat terrain is in your favor and so is the cost at only $400. Keep the blades sharpened, power down the engine some to engage the mower, let the mower get up to speed and then increase the throttle up to PTO speed. You can always adjust how wide a swath you are cutting or slow your tractor speed if the grass growth gets taller than you would normally cut. Be happy, you got a good deal. If it's not what you hoped, you can still sell it an get a smaller mower. You are in a win, win situation!
Let us know how it goes so that others can make a more informed decision using your experience.

Paul

 

[Eric McCarthy]

I see too many bad things here happening. General rule of thumb is 5 horse power per foot of implement. I know its a matter of just 5 small horse power but it can make all the difference in the world when it comes to your engine. To much power it lost to begin with trying to turn the blades. Which require a certain amount of feet per second blade tip speed. I think honestly its way over kill and could cause to much harm and damage not to mention more fuel trying to power it.

 

[KenB2920]

Wow, everything I am about to say will probably contradict itself.

I have twice your pto hp and will be running a mower only one foot wider than you are anticipating.

Now, we can definitely agree a diesel tractor hp rating is deifinitly stronger than a gas lawnmower engine. I have a 13 or 14 hp gas Kawasaki engine that runs a 50 inch walk behind. You are considering 2 more feet but also have diesel power behind you.

I still think you're pushing it. Now is this just to get you by for now or a permamant deal? I don't see it as a problem if you use it to get you by. Indent think it will last you 5 years.

 

[hodge]

I think it is too much mower. It may not hurt the drivetrain, but you are going to deal with stalling, working the clutch more, and possible overheating. A good deal isn't any help if you can't use it. I think a 5' mower would be preferable.

 

[76_Bronco]

This post > http://www.orangetractortalks.com/forums/showthread.php?t=366&highlight=b7100+finish+mower was the deciding factor in my recent purchase of a 72" mower for my 17hp tractor. But I won't hold Vic responsible if my 7200 can't handle that much mower

 

[Eric McCarthy]

Now, we can definitely agree a diesel tractor hp rating is deifinitly stronger than a gas lawnmower engine. I have a 13 or 14 hp gas Kawasaki engine that runs a 50 inch walk behind. You are considering 2 more feet but also have diesel power behind you..

Geez I run a 14hp Kohler motor on a 44inch Toro Proline and sometimes it feels like the 14hp isn't enough to cut.

 

[Bulldog]

This post > http://www.orangetractortalks.com/forums/showthread.php?t=366&highlight=b7100+finish+mower was the deciding factor in my recent purchase of a 72" mower for my 17hp tractor. But I won't hold Vic responsible if my 7200 can't handle that much mower

My B7100 must have been weak I guess, a 48" mower was all it could handle in good thick grass.

I've now got 32hp (27 pto) with a 72" mower and in thick grass it's all my tractor wants. I can't imagine trying to pull a 72" mower with a B7200. JMHO

 

[G-Man]

Question, are you talking about a 72" FINISHING mower or a 72" BUSH HOG rotary mower? These are to total different beasts and operate with different principles. You will not able to use a 72" bush hog rotary mower with just 14hp. You will in fact work you tractor to death. If you have a finish mower which is like a mower deck under a riding mower you will be in better shape. You will have to go slow but can mow. I have a 60" ZTR and it does fine until I get to thicker stuff then have to use the tractor with a 48" rotary mower deck. I have mowed stuff as tall as the hood with the bush hog just fine, but the very best rule of thumb is 5 engine hp per foot of mower.

 

[Eric McCarthy]

He said he bought a finishing mower manufactured by Bush-hog.

 

[Kubota Newbie]

I've got a 18 Kohler on a 54 inch tow behind finish rig and in really heavy grass it sure knows it's there, and it doesn't have to run the driveline on a tractor too. I'd think that would be too much for that size tractor. They would put 60 inch decks on the old Farmall/International Cub tractors, they were rated about 14 HP and that's generally all they wanted.

BTW, a horsepower is a horsepower is a horsepower. Diesel, gas, steam, dog farts, it doesn't matter what the fuel source, it's all the same unit measure of power.
A diesel often has greater torque rise than a gas, meaning it doesn't loose power (in measured HP) as quickly when the RPM's start to drop off because it may make more torque for a given lower RPM below the rated HP level. Which in turn makes it "seem" to have more power( ie. it lugs better). Either engine, rated at 14 HP will do exactly the same amount of work per unit of time if both are kept in their rated peak HP RPM range.

 

[76_Bronco]

How did the 72" Bush-hog finish mower work out for you mjp1966? My B7200 did great with the 72" Land Pride on a 1 1/2 acre flat field.

 

[rodbuilder]

Sell it and by a 5 footer. You'll be a LOT happier and so will your Kubota.