Help Matching PTO Horsepower with Finish Mower Size??

[coastalguy]

Does anybody know guidelines for how much pto horsepower various finish mowers need. I am looking at buying a tractor and a 84" woods deck and was wondering what size tractor I need. I want to make sure I can maintain the blade speed and not strain the tractor.

Thanks

 

[RoyJackson]

I ran a 60" unit behind a 16.5 PTO HP tractor for a couple years with no problems whatsoever.
My current tractor with 24 PTO HP, could easily handle a 72" RFM and perhaps an even large mower on level land.

So, I'd suggest you'd want 22 to 28 PTO HP to operate an 84" mower. This assumes you cut regularly Of course, you can always make a partial pass (not the full width of the mower), if the grasses are really thick.

22 to 28 HP gives you a lot of choices for a tractor. That's several Kubotas, Deeres and New Hollands.

However, the weight of that large mower may be more of a factor. Mowers that size are upwards to 1000 lbs (± 200 lbs). You'll want front weights of some sort.

 

[dieselsmoke1]

84" is a big puppy. Hope you don't have too many trees.

Have not tried a finish mower with my current piece, however can say that 35 hp barely even flinches with a 72" . I would expect to be able to run an 84" with my 28hp under normal conditions.

 

[Bob_Skurka]

Does anybody know guidelines for how much pto horsepower various finish mowers need. I am looking at buying a tractor and a 84" woods deck and was wondering what size tractor I need. I want to make sure I can maintain the blade speed and not strain the tractor.

Thanks

Approximately 3pto HP per 12" of mower deck is a good rule of thumb for a finish mower assuming a typical lawn.

 

[sandman2234]

The horsepower needed also depends on the speed at which you intend to mow. Ground speed or how fast you are shoving the grass into the mower also eats horsepower. If your the type that needs it done right now, and can't wait till you get to the other end before you turn to get that next pass done, then a few extra horsepower might be needed.
I went from a 13 hp tractor pulling a 4' mower, to a 67 hp tractor, and a 78" flail mower. The tractor wouldn't run fast enough (and stay on the ground) to load it as much as the small tractor did.
I slowed down and get a lot better cut than I did trying to see how fast it would cut it.
David from jax

 

[djradz]

I'm going to contradict a few of the posters so far - sorry guys. The figure I think will lend itself to more acceptable results if about 5 hp/foot, especially if you are cutting anything more than a pretty well maintained lawn and moving at anything more than a relatively slow speed. Anything less and you'll have to move slowly or overlap passes.