Is my Flail Mower too big for my 'new' Kubota B7001 / B7100?

[4WDuke]

Hi all,

1st time poster and 1st time tractor owner!

Long post to provide the detail, but the key question is: Am I going to break this little tractor if I try out a flail mower that's probably too big for it?

I've bought a re-manufactured Kubota B7001 4WD Sub-Compact (which I believe is the Japanese domestic / Asian model no for a B7100). The seller had imported a few containers of re-manufactured B6001s and B7001s and implements from Japan to Australia 5 or 6 years ago and is selling off the last couple that have been in storage unused since then.

My package deal is with a FEL, 4'(?) slasher (what Aussies call a rotary mower / brush hog) and a flail mower. The clean (no implements) B7001 in the pics is mine. Please also see pics of a B6001 he's currently fitting an FEL (including Sub Frame) to - my FEL will be identical and fitted before collection. The seller has several older (original) Kubota B series, so we got to see the equivalent slasher in use behind his older, even less powerful 2 cylinder B6000 and it worked well slashing the same thick Kunzea (Tea Tree family) bush that we have all over our property.

On specs, the flail mower is too big for the tractor. I'd like to try it and see how well it works anyway, if I'm not going to damage anything trying. If it's too big, I'll keep it anyway as I can probably do a deal with a neighbour to use my flail mower on his larger tractor when needed for both properties. The seller said he imported some flail mowers based on demand, but has never used one and knew less about how they work they I did from my online research.

Key specs:

Kubota B7001 (fr TractorData website + B7100 Manual)

- 490kg (1080lbs) dry / no implements
- 17HP
- Slasher max rating 140kg (300lbs)
- Lower link max load rating 180kg (400lbs)
- Rotary Tiller max 180kg (400lbs)
- Backhoe max 270kg (600lbs), Sub Frame Necessary
- FEL max 227kg (500lbs), Sub Frame Necessary

Flail Mower: Lefa EFG-125 (Chinese)

- 230kg
- 24 Hammers
- Recommended 30-40 Hp Tractor
- https://www.lefa-cz.com/product/Flail-mower-EFG.html

I've seen similar spec'd flail mowers rated at 25+ HP and 20+ HP. I imagine (for tractor rating) that a flail mower is more similar to a rotary tiller than a slasher based on shorter overhang (so take the 180kg Kubota rating)?

Will the FEL subframe increase rear load rating on the tractor like the Backhow Specs? Obviously the FEL will provide good counter weight too.

So, do I try it or do I risk damaging the tractor by even trying?

Thanks!

 

[D2Cat]

How wide is the flail mower? It weight a bit over 500 lb, correct? That seems a bit heavy for a B7100, however that may be shipping weight, and when you get it attached to your tractor it may be more like 400#. No matter, it's part of your deal!

You can mow with it and if the grass is too thick just raise up the mower a bit for the first go around. Then re mow with the mower at the finish cut height. Then if you think the mower is too wide, just don't take a full cut on the second and continual laps.

That's a nice machine and set up. Have fun!!

 

[SDT]

Hi all,

1st time poster and 1st time tractor owner!

Long post to provide the detail, but the key question is: Am I going to break this little tractor if I try out a flail mower that's probably too big for it?

I've bought a re-manufactured Kubota B7001 4WD Sub-Compact (which I believe is the Japanese domestic / Asian model no for a B7100). The seller had imported a few containers of re-manufactured B6001s and B7001s and implements from Japan to Australia 5 or 6 years ago and is selling off the last couple that have been in storage unused since then.

My package deal is with a FEL, 4'(?) slasher (what Aussies call a rotary mower / brush hog) and a flail mower. The clean (no implements) B7001 in the pics is mine. Please also see pics of a B6001 he's currently fitting an FEL (including Sub Frame) to - my FEL will be identical and fitted before collection. The seller has several older (original) Kubota B series, so we got to see the equivalent slasher in use behind his older, even less powerful 2 cylinder B6000 and it worked well slashing the same thick Kunzea (Tea Tree family) bush that we have all over our property.

On specs, the flail mower is too big for the tractor. I'd like to try it and see how well it works anyway, if I'm not going to damage anything trying. If it's too big, I'll keep it anyway as I can probably do a deal with a neighbour to use my flail mower on his larger tractor when needed for both properties. The seller said he imported some flail mowers based on demand, but has never used one and knew less about how they work they I did from my online research.

Key specs:

Kubota B7001 (fr TractorData website + B7100 Manual)

- 490kg (1080lbs) dry / no implements
- 17HP
- Slasher max rating 140kg (300lbs)
- Lower link max load rating 180kg (400lbs)
- Rotary Tiller max 180kg (400lbs)
- Backhoe max 270kg (600lbs), Sub Frame Necessary
- FEL max 227kg (500lbs), Sub Frame Necessary

Flail Mower: Lefa EFG-125 (Chinese)

- 230kg
- 24 Hammers
- Recommended 30-40 Hp Tractor
- https://www.lefa-cz.com/product/Flail-mower-EFG.html

I've seen similar spec'd flail mowers rated at 25+ HP and 20+ HP. I imagine (for tractor rating) that a flail mower is more similar to a rotary tiller than a slasher based on shorter overhang (so take the 180kg Kubota rating)?

Will the FEL subframe increase rear load rating on the tractor like the Backhow Specs? Obviously the FEL will provide good counter weight too.

So, do I try it or do I risk damaging the tractor by even trying?

Thanks!

Doubt if you will break anything but your tractor does not have enough power to operate it properly and you will need front weights.

SDT

 

[UpNorthMI]

2nd comments from SDT.

You will not be happy due to the lack of power giving you overall performance issues. I'm sure you can mount it and it will operate, it will just not run like it is supposed to.

 

[4WDuke]

How wide is the flail mower? It weight a bit over 500 lb, correct? That seems a bit heavy for a B7100, however that may be shipping weight, and when you get it attached to your tractor it may be more like 400#. No matter, it's part of your deal!

You can mow with it and if the grass is too thick just raise up the mower a bit for the first go around. Then re mow with the mower at the finish cut height. Then if you think the mower is too wide, just don't take a full cut on the second and continual laps.

That's a nice machine and set up. Have fun!!

Thanks mate,

External width is 1450mm / 57", and cutting width is 1250mm / 49".
Weight - yes 230kg is about 507lbs on the old scale. 230kg is on the online specs (link in the OP) and stamped on the serial number plate on the machine body, so I'd expect it's implement weight, not shipped weight.

 

[4WDuke]

Doubt if you will break anything but your tractor does not have enough power to operate it properly and you will need front weights.

SDT

Thanks SDT,

That's sort of what I was hoping and expecting. Ie hoping to hear I should give it a go as I'm unlikely to break anything but don't expect too much!

Will the FEL be enough front weight or should I pick up half a bucket of rock / dirt too?

 

[4WDuke]

2nd comments from SDT.

You will not be happy due to the lack of power giving you overall performance issues. I'm sure you can mount it and it will operate, it will just not run like it is supposed to.

Thanks mate. I didn't go too much into what I was hoping to achieve in the first post because my main concern is whether I was likely to damage anything in trying. But I've got a 17 Acre property covered in Kunzea (thick Tea Tree bush). My neighbour has slashed 5 acres or so already, but the locals tell me that best way to kill the Kunzea off is to mulch it in the heat of summer. Unfortunately there is also a fair bit of rock laying around, especially as the gradient increases heading up the hill. The slasher is working, but leaves a lot of cut bush in windrows and the bush is re-growing 12mths on. It's also pretty hard on the slasher, because my neighbour has been trying to do it in one pass and keeps hitting rocks. Pics that follow looking uphill were taken a few months after slashing. Looking downhill is about 12mths after slashing - a lot of the cut Kunzea has rotted away and there is plenty of low fresh growth.

From what I can gather a 'right sized' combo of tractor and flail mower would be best for the job, but still might need to be done in 2 goes - 1st cut a foot high so that I can see and remove the rocks, then 2nd pass nice and short in the heat of summer to kill the Kunzea. With both implements I might be able to do 1st pass with the slasher, then only use of the flail mower on the short stuff (if the tractor can handle it) which is why I'm hoping I can give it a try without damaging the 3point linkages (or axle or chassis) by. If that's still too much for it I'll see if we can use my flail mower with my neighbours old Ford 1500.

 

[D2Cat]

4WDuke, be sure to check the "sheer" pin (or slip clutch) on the PTO shaft of the tiller. You want the pin to give up before any other parts fail. The slip clutch, if it has one, needs to be adjusted to allow slippage at a heavy load.

Also, when mowing have the PTO at rated speed for implement, probably 540. If you run at a lower RPM cutting effectiveness is deminished.

 

[Lencho]

You may have seen this video of a b7100 running a flail:

At 3:21 it is easy to read the flail mower is 85cm wide. I think these are available in 95 and 105cm widths as well. My concern is PTO hp more than the weight.

 

[4WDuke]

Thanks D2Cat - will check, and yes, both my implements are rated at 540.

Lencho - yes I found that one thanks. I'm expecting the 125mm flail to work sub-optimally at best, but just don't want to risk breaking anything to prove it!

 

[Lencho]

Can you try it out? I don’t see how it would damage your tractor. If you don’t have the PTO hp to spin it I think it will just be ineffective or bog down and maybe kill your engine. Shouldn’t be any real damage. You can run it high on the first pass and then take a second pass. The 125 cm is just over your tire width so that is great! Those tree stubs may puncture your tires so be careful there.

 

[4WDuke]

Can you try it out?

Yep, that's the plan at this point. Picking up next weekend. Overloading the 3 point / lower link was my main concern but I'm going to give it a try.

 

[Lencho]

No worries on the TPH, my tiller is 500 pounds and it lifts it fine. I actually like the tiller for heavy FEL work, it keeps the steering light!

 

[4WDuke]

No worries on the TPH, my tiller is 500 pounds and it lifts it fine. I actually like the tiller for heavy FEL work, it keeps the steering light!

Excellent - that's exactly the reassurance / 1st hand experience I was looking for (presuming your B7100HST and my B7001 are structurally the same). My flail mower is stamped 230kg (507lbs). Thanks!

 

[Lencho]

No concern about the weight. Consider a slip clutch on the PTO shaft to protect your PTO if the flail jams on something.

 

[4WDuke]

Feedback for anyone interested and in case anyone finds this post in a search with a future query:

It works fine, just not fast! The PTO will lift the flail mower and move it around fine (I'm glad to have the FEL on as counter weight though). In areas that are largely grass with 12 months growth, I can move along in about 3rd gear low range, but when I start getting into the Kunzea ( thicker bush in the Tea Tree Family), I'm down to 2nd gear low range. When the Kunzea gets 4' high and so dense I'm relying on the FEL bucket to find stumps and rocks I cant see, it will still plod along in 1st gear low range. In the dense thickets where it is 5' - 6' high it will start to stall, so I just lift the flail mower up so it hangs on the 3 Pt about 1' above ground level for 1st pass and drop it onto the skids for 2nd pass (both 1st gear low range). Its going to be slow clearing 17 Acres like that, but I'm thinking of it as a labour of love! Besides, I should only ever need to deal with the full growth once, then just maintain it after that!

I've even mown down a black wattle / acacia tree with it. It was about 20' high with a 4" diameter at the base. Pushed it over the the FEL bucket and passed over holding the flail mower at max height on the 3Pt which mulched most of the foliage, then it probably took another 5 passes progressively lowering the flail, but in the end nothing was left but mulch and a shredded 3" high stump!

I've tried a comparison in thick grass 1-2' high between the flail mower (which as per the early posts, is too big for the tractor) and a better matched 4' slasher. In the thicker grass, you're running one gear lower (slower) with the flail mower vs the slasher (low 2 vs 3), but much better result without the clippings all piles up in windrows. I haven't tried the slasher in our Kunzea, because a neighbour previously did some for us with much bigger tractor and slasher. The windrows are still there 18mths later and it we've got too much rock so it was launching softball sized rocks with about a 50m danger zone. I think that would probably kill our little slasher, but the flail mower handles the rocks better if you don't see them and react in time - they make a hell of a noise, but a quick lift on the PTO and they roll harmlessly out the back.

Thanks for all the advice above folks!

 

[Vigo]

Glad you just went for it, usually the main difference between too little hp and enough is just how quick you can work. Labor of love indeed! But the 7100 sure is fun to use (i have 6100 and 7100 as a parts tractor) and it sort of makes how long things take less annoying because you can have fun on the thing for a good while before it starts to get old.

At least you're not doing what i did.. I knocked over about 2.5-3 acres of 3ft tall straw grass with a 42" riding mower at a crawl before i bought a tractor with a 'slasher' (b6100), and guess what.. I've STILL never hooked up that slasher because now that i did the job the wrong way i don't need it!!! Use the loader and box blade as often as i can, though!