hp needed

[boatmoter]

I currently run a Kubota M6800 to use a 7' land pride brush cutter and 7' snowblower. 68 hp. Even with sharp blades, some real thick grasses makes tractor work harder than i'd like. I usually mow in first to get it all. Would 90hp give me the umph I'm looking for and perhaps give me enough to maybe go to a single batwing 10 footer. Some mowing is also red brush and tag alders. If I can drive over it it gets cut. Would not use the 10' for heavy brush. Thoughts?

90HP would turn a 15ft batwing mower. would be a bit of overkill for a 7 footer

 

[WR701]

I currently run a Kubota M6800 to use a 7' land pride brush cutter and 7' snowblower. 68 hp. Even with sharp blades, some real thick grasses makes tractor work harder than i'd like. I usually mow in first to get it all. Would 90hp give me the umph I'm looking for and perhaps give me enough to maybe go to a single batwing 10 footer. Some mowing is also red brush and tag alders. If I can drive over it it gets cut. Would not use the 10' for heavy brush. Thoughts?

I have a wild area filled with grasses, weeds, brush and saplings that I mow once a year with my 60hp L6060 using a 7' medium duty Bush Hog brush cutter. By the time I mow the weeds and brush they are usually around 4' high. I generally run my tractor at 2000 RPM in mid-range (hydro with 3-speed gearbox) and don't have any issues. When I first got my L6060 I had not mowed the area for several years and there were dozens of 1"-2" thick saplings which did not pose a challenge, although I did have to slow down some. On occasion I have even cut down 3" trees, which is about all the mower is capable of. It does not seem likely to me that power is an issue, which make me wonder whether you might have bought a light duty brush cutter. Have you checked the HP rating of the one you have?

 

[kthompson]

Haven't mowed some of these areas in a few years and most of it was above the loader arms. Can't go any slower than first gear without riding the clutch! If I had time to mow it all twice a year it wouldn't be an issue. Some years am too busy to get at secondary projects. There's a line between doing and over doing. Ill air on the side of caution. Thanks

I have the same tractor, you are saying you use first gear: high range I am certain. Yes that tractor has a high and low range and dropping to 4th in low range is not much a speed drop but with what you are doing could be a big help. Tall thick grass is the hardest cutting I have ever run any rough cut mower in.

If running hot, check the air intake and filter. Low air flow will cause power loss and running hot.

 

[5030]

You're at 62 pto hp on a 7' cutter.

That should be more than enough. What's your version of "working too hard"?

Is it overheating? Could just be chaff in the radiator, which is the bane of all mowers really.

Easily corrected with a electrical reversing radiator fan which is exactly what I did on both my Kubota M9's and I deleted the power robbing fixed fan blades and spacers on both as well. You can buy electrical reversing fans on may websites that are large enough to fit in the radiator shroud on any tractor and affixed with metal 'L' brackets screwed to existing shroud. The only negative aspect is you will have to have a sufficient alternator output to cover any and all your electric amperage needs plus the fan draw, something I have as my units have 75 amp alternators on both and plenty of reserve battery capacity as well as I run Group 31 starting batteries with 1000 CCA.

 

[5030]

Far as 'bogging down under load', I just keep an eye on the rpm and when the implement (whatever it is) pulls the rpm below the maximum torque output (which is in your owners manual if you have ever bother to read it), I either slow down or drop a gear.

All diesels are designed to run hard at maximum torque output, unlike gas motor. besides, it's good for the engine, keeps the deposits out of the cylinders and off the vale seats too.

In my case, I want to see a little smoke as that tells me the engine is happy.

 

[Williy]

Perhaps going slower giving the cutters a little time to do their
job

willy

 

[5030]

Don't know about the injection. It's an '03.

Should be mechanical and you have to look at the pump and see it there is a fuel rail or individual injector lines. I cannot look for you, you have to.

My tractors are all gear drive, hydraulic shuttles which means no dry clutch to wear out., Only way I buy them and both have 12 speed gear boxes but only the 2 bottom ranges are synchronized which is no big deal for me as I learned long ago how to 'float my gears', I rarely use the hydraulic shuttle except when changing directions using the bucket. In fact, last shop visit, my mechanic checked the lockup pressure on the shuttle wet clutch and it was in Kubota spec and I've never had to adjust the free play on the pedal which is 1/2" to engagement. That is at 6500 meter hours on one and 4500+ on the other. Far as lugging down the engines. if I start to see black smoke from the exhaust stack, I drop a gear, I have plenty to choose from. I'd never have a hydrostat. I've had around 10 Kubota's in my lifetime and a few hydrostats as well and they don't work for me with what I do. Too much parasitic loss in power and too noisy too.

Now if Kubota came out with a CVT, I might consider one.

 

[jmc]

Another thing is to confirm that the front of the rotary cutter is set lower than the rear. Otherwise, the blades are in contact with the grass for 360* instead of 180*.

In my brush/grass, when things bog down, I just move over to lessen the swath width.

 

[mo1]

I currently run a Kubota M6800 to use a 7' land pride brush cutter and 7' snowblower. 68 hp. Even with sharp blades, some real thick grasses makes tractor work harder than i'd like. I usually mow in first to get it all. Would 90hp give me the umph I'm looking for and perhaps give me enough to maybe go to a single batwing 10 footer. Some mowing is also red brush and tag alders. If I can drive over it it gets cut. Would not use the 10' for heavy brush. Thoughts?

A cutter will bog down if you stuff too much through it too quickly, regardless of how much engine power there is. Slowing down to first gear is sometimes needed just so the cutter has enough time to shred the material fed into it. I have to do this if I am cutting blackberry thickets next to the fence lines, if I go faster than that it bogs and slips the slip clutch. You have more than plenty of power for a 7' cutter, you should be slipping the slip clutch or shearing bolts well before you bog down the tractor engine, assuming everything is set up properly. If not, you should check your slip clutch to make sure it isn't seized or over-tightened or that somebody didn't put a Grade 8 bolt in for a shear bolt. A 68 HP tractor should be able to run a 10-12' cutter, and even a 15'er if you are doing something lighter duty like pasture clipping. A 90 HP should run a 15'er in most conditions.