Mini Excavator Questions

oldafretired · Jan 19, 2017

Looking for a replacement for a BH77 backhoe on a Kubota L3901 tractor. I let my brother use the L3901 to move snow this winter since his old tractor broke down. I'll probably end up giving him the tractor and BH77 so I won't have a backhoe anymore. I've been using the backhoe to mainly dig up stumps after cutting down pine trees on my heavily forested 10 acres. The largest stumps are probably 15" in diameter or so but most are smaller.

I think it used to take me over an hour with the BH77 to dig up the larger stumps using a 16" bucket. I'm thinking of getting a mini excavator to replace the backhoe. I really want to be able to put the excavator in my shop which has a garage door opening that is 96.5" high so the choices become limited. The Kubota KX71-3S and KX91-3S2 are right at 96" high according to their specs so if the specs are accurate, either should fit. The KX71 with cab is supposed to be a half inch shorter but I prefer an open station. Would either one of these excavators be good for removing stumps and would they should be able to get a pine stump out significantly faster than the BH77? What kind of performance difference would there be between the KX71 and KX91?

Thanks!

Ken45101 · Jan 20, 2017

IIRC, pine trees are shallow rooted and do not have tap roots? Sandy soil? In that case, the little mini-s might do the job. I would look closely at the specs (digging force, breakout force, etc.) and compare ihem to your backhoe.

I have a KX-121 and I have difficulty digging stumps out with it, but usually that is larger stumps and they have heavy deep roots and tap roots in heavy clay soil.

oldafretired · Jan 20, 2017

Ken45101 said:
IIRC, pine trees are shallow rooted and do not have tap roots? Sandy soil? In that case, the little mini-s might do the job. I would look closely at the specs (digging force, breakout force, etc.) and compare ihem to your backhoe.

I have a KX-121 and I have difficulty digging stumps out with it, but usually that is larger stumps and they have heavy deep roots and tap roots in heavy clay soil.

Some have something like a tap root but most don't seem to. The soil is mainly rocky but not difficult to dig with a backhoe. Here's some photos of stumps the BH77 dug out.

kthompson · Jan 20, 2017

There is another possible option depending on your needs. If you are able to take a week at the time or a month is even better to just rent a machine. I did some price checking for a person who really want me to take my machine and do some work for him (I do not hire out for work) and found a price with a dealership that almost shocked me, a 16,000 pound machine at $500 per week with my providing insurance on it. That was less than a true rental company was for a $6,000 machine. Now delivery was $200 each way for about 20 miles as they only had a lowboy that would haul that load. But for a 8 ton machine you should find it very quick on what you describe.

oldafretired · Jan 20, 2017

kthompson said:
There is another possible option depending on your needs. If you are able to take a week at the time or a month is even better to just rent a machine. I did some price checking for a person who really want me to take my machine and do some work for him (I do not hire out for work) and found a price with a dealership that almost shocked me, a 16,000 pound machine at $500 per week with my providing insurance on it. That was less than a true rental company was for a $6,000 machine. Now delivery was $200 each way for about 20 miles as they only had a lowboy that would haul that load. But for a 8 ton machine you should find it very quick on what you describe.

Thanks for bringing up the renting idea but I'd rather just buy one since I'd be pulling stumps here and there on and off for years.

Code54 · Jan 20, 2017

I bought a KX91 this summer and am extremely pleased with it. Been doing some clearing, stumping, etc...
The photos are a small tree I had to cut up
Stump I dug out (that one was big and DEEP and took about 45 or so minutes I believe)
The fire pit I dug (really is about 8'x10x'4'
The others are of a road I built for the ATV (that was about 1:45-2hrs work
The last is a trench for a generator (was a 50' maple there the day before - tree and stump gone but no photos)

oldafretired · Jan 20, 2017

Code54 said:
I bought a KX91 this summer and am extremely pleased with it. Been doing some clearing, stumping, etc...
The photos are a small tree I had to cut up
Stump I dug out (that one was big and DEEP and took about 45 or so minutes I believe)
The fire pit I dug (really is about 8'x10x'4'
The others are of a road I built for the ATV (that was about 1:45-2hrs work
The last is a trench for a generator (was a 50' maple there the day before - tree and stump gone but no photos)
View attachment 495858 View attachment 495859 View attachment 495860 View attachment 495861 View attachment 495862

Wow! Thanks for the great photos. Looks like it will do everything I could ask for. I'm planning of making a small road around the perimeter of my almost 11 acres just like what you did. Thanks! If you have a chance could you measure the actual height of the excavator from the ground to the highest point of the excavator? I'd like to find out if it will fit through my garage door opening. Thanks again!!

4570Man · Jan 21, 2017

Just looking at specs the KX91 is considerably stronger than the BH71. I've used a John Deere 50D which is quite a bit bigger than the KX91, but comparing it to my Kubota BH90 backhoe is like comparing your backhoe to a shovel with a lazy person using it. We rented a Wacker Neuson 50 Z3 to dig out a pond. It was terrible. It had inadequate counter balance, the boom drifted to the right and wouldn't come back, and although the specs are similar it's nowhere near as strong as the Deere 50D.

Oldtractorfixer · Jan 21, 2017

I just finished shopping for a replacement for our Takeuchi TB125. This is a 6000lb machine, a little smaller than the ones referenced here. I compared John Deere, Takeuchi, Kubota and Cat. I found Takeuchi TB230 to be the best buy. It was a little more than the John Deere and a lot less than the Kubota which was a lot less than the Cat. The John Deere did not have near the breakout force and was lighter built than the others. Just saying you need to shop seriously on these.

oldafretired · Jan 21, 2017

4570Man said:
Just looking at specs the KX91 is considerably stronger than the BH71. I've used a John Deere 50D which is quite a bit bigger than the KX91, but comparing it to my Kubota BH90 backhoe is like comparing your backhoe to a shovel with a lazy person using it. We rented a Wacker Neuson 50 Z3 to dig out a pond. It was terrible. It had inadequate counter balance, the boom drifted to the right and wouldn't come back, and although the specs are similar it's nowhere near as strong as the Deere 50D.

Oldtractorfixer said:
I just finished shopping for a replacement for our Takeuchi TB125. This is a 6000lb machine, a little smaller than the ones referenced here. I compared John Deere, Takeuchi, Kubota and Cat. I found Takeuchi TB230 to be the best buy. It was a little more than the John Deere and a lot less than the Kubota which was a lot less than the Cat. The John Deere did not have near the breakout force and was lighter built than the others. Just saying you need to shop seriously on these.

Hey, thanks for the good info. I guess the KX91 should me more than adequate for what I'll use it for. I looked at the Takeuchi height and it's a bit too tall to fit through my shop door. I should have had a taller door put but I never considered getting an excavator at the time.

MinnesotaEric · Jan 21, 2017

4570Man said:
Just looking at specs the KX91 is considerably stronger than the BH71. I've used a John Deere 50D which is quite a bit bigger than the KX91, but comparing it to my Kubota BH90 backhoe is like comparing your backhoe to a shovel with a lazy person using it. We rented a Wacker Neuson 50 Z3 to dig out a pond. It was terrible. It had inadequate counter balance, the boom drifted to the right and wouldn't come back, and although the specs are similar it's nowhere near as strong as the Deere 50D.

I'm happy I stumbled upon this remark as I've been thinking about visiting my local Gehl dealer because of the tilting cab option. If looking at the Deere 50, look at the Hitachi ZX50 as it is the same machine.

Code54 · Jan 21, 2017

Checked the Mini today - 8' and about 3-4 to 1 inch (trying to keep the tape straight) - there is a loop on the roof to lift the ROPS off and that adds a little bit to the height, maybe an inch. I included the loop. My shop has an 8' door but it is a slight slope from the outside up to the concrete - it is just enough the top of the ROPS hits the trim (the tracks don't stay flat and the front lifts a bit with the slope) and I can't quite get it in. If your entry is flat and you take that little loop off the roof with a grinder you maybe able to slip it in the garage.

oldafretired · Jan 21, 2017

Code54 said:
Checked the Mini today - 8' and about 3-4 to 1 inch (trying to keep the tape straight) - there is a loop on the roof to lift the ROPS off and that adds a little bit to the height, maybe an inch. I included the loop. My shop has an 8' door but it is a slight slope from the outside up to the concrete - it is just enough the top of the ROPS hits the trim (the tracks don't stay flat and the front lifts a bit with the slope) and I can't quite get it in. If your entry is flat and you take that little loop off the roof with a grinder you maybe able to slip it in the garage.

Thank you very much for taking the time and effort to measure it. My shop has a metal roll up garage door for an 8' opening but the opening height is actually 1/2" higher so it will most likely fit. So the ROPS is removable? Wonder how difficult it is to take it on and off?

Do you store your excavator outdoors since it doesn't fit through your door? I know dealers just keep their tractors and excavators outdoors so I guess it's not a problem.

Code54 · Jan 21, 2017

Glad to help!
The ROPS is removable but it would take a bit plus it is heavy - can't just unbolt the top bar or something like that, it is sort of all or nothing. The roof and bars are all one piece but it can be removed but not something you would want to do every day. I was thinking of pulling mine off when I need to do a big service (like all fluids, track work, etc) so I can just drive it into my shop.
I store mine in an unheated building with a gravel floor - door is about 8 1/2' plus the gravel is a bit low so I have some extra room to get in there. That way it stays dry and out of the sun.
Look around for used also, I bought this one with 235ish hrs on it and that saved a TON of money. Yes it had nicks and scrapes and the rubber track had some minor damage (looked like someone tried to work too close to the crub) but for almost 20K off new I will live with it!

oldafretired · Jan 21, 2017

Code54 said:
Glad to help!
The ROPS is removable but it would take a bit plus it is heavy - can't just unbolt the top bar or something like that, it is sort of all or nothing. The roof and bars are all one piece but it can be removed but not something you would want to do every day. I was thinking of pulling mine off when I need to do a big service (like all fluids, track work, etc) so I can just drive it into my shop.
I store mine in an unheated building with a gravel floor - door is about 8 1/2' plus the gravel is a bit low so I have some extra room to get in there. That way it stays dry and out of the sun.
Look around for used also, I bought this one with 235ish hrs on it and that saved a TON of money. Yes it had nicks and scrapes and the rubber track had some minor damage (looked like someone tried to work too close to the crub) but for almost 20K off new I will live with it!

Yup, the prices on new ones sure are high but used with low hours are probably pretty hard to find. Glad you found a nice one!

One option might be to just cut the ROPS down a couple inches and weld it back in place. We've done roll bars for race cars.

Thanks again for your help.

BukitCase · Jan 22, 2017

One thing you may wanna consider whether you get another BH or a mini-ex - since you stated you'll be doing quite a bit of stump removal, think about adding not only a thumb but also a single ripper - this concentrates ALL the power you have into a narrow area.

My old 580B is gonna get a thumb AND a single ripper when I get to it, for the same use you have. When I fab my ripper, the inside curve is gonna get 1-1/2x3x1/2" AR plate "dominos" welded in place with each successive one resting on the previous one so they form wide saw teeth, because I also have some 100' tall firs that need to become firewood, and their roots are enough to slow down even a full size excavator a bit.

With my "teeth" arrangement, crowding and lifting at the same time should cut clear through a 8" root in just a few passes.

Here's a thread on one TBNer's version, do a search on "single ripper" - should turn up several more...

http://www.tractorbynet.com/forums/attachments/185530-added-ripper-my-woods-bh90x.html

HTH... Steve

Code54 · Jan 22, 2017

Since you are used to working on roll bars I doubt it will be a real big deal. Thought about taking mine off and having it cut down 2" myself. (Just want someone that is a better welder to do it).

I have a 12", 24" and then a 36"(smooth - no teeth) bucket and quick attach for mine. It works great - 12" for stumps and trenching, 24" for normal digging and the 36" for cleaning out my ditch lines and moving/loading material. I found I change buckets all the time depending on what I am doing as it only takes a minute or so. Not worth working with a bucket that is not perfect for the task when you have the quick detach - to me at least, it is well worth the money (as well as a hydro thumb)
One of these days I would like to get a ripper and a brush mower but those mowers cost are crazy expensive so that may not happen unless I get lucky and find a deal....

oldafretired · Jan 22, 2017

BukitCase said:
One thing you may wanna consider whether you get another BH or a mini-ex - since you stated you'll be doing quite a bit of stump removal, think about adding not only a thumb but also a single ripper - this concentrates ALL the power you have into a narrow area.

My old 580B is gonna get a thumb AND a single ripper when I get to it, for the same use you have. When I fab my ripper, the inside curve is gonna get 1-1/2x3x1/2" AR plate "dominos" welded in place with each successive one resting on the previous one so they form wide saw teeth, because I also have some 100' tall firs that need to become firewood, and their roots are enough to slow down even a full size excavator a bit.

With my "teeth" arrangement, crowding and lifting at the same time should cut clear through a 8" root in just a few passes.

Here's a thread on one TBNer's version, do a search on "single ripper" - should turn up several more...

http://www.tractorbynet.com/forums/attachments/185530-added-ripper-my-woods-bh90x.html

HTH... Steve

Thanks for the advice. I'd definitely get a hydraulic thumb and a ripper. I saw a video where a miniex was digging stumps out with a ripper and the holes were smaller than using a bucket which means less work to fill the hole. A ripper with teeth should work great for cutting through tough roots.

Code54 said:
Since you are used to working on roll bars I doubt it will be a real big deal. Thought about taking mine off and having it cut down 2" myself. (Just want someone that is a better welder to do it).

I have a 12", 24" and then a 36"(smooth - no teeth) bucket and quick attach for mine. It works great - 12" for stumps and trenching, 24" for normal digging and the 36" for cleaning out my ditch lines and moving/loading material. I found I change buckets all the time depending on what I am doing as it only takes a minute or so. Not worth working with a bucket that is not perfect for the task when you have the quick detach - to me at least, it is well worth the money (as well as a hydro thumb)
One of these days I would like to get a ripper and a brush mower but those mowers cost are crazy expensive so that may not happen unless I get lucky and find a deal....

You have a great bucket assortment. That's a pretty big investment but sure is nice to have.
I plan to get the quick attach but are they universal so any attachment for a quick attach will fit? Do they make rippers for the quick attach?

Code54 · Jan 23, 2017

The quick attach is not really universal, it is specific to the actual machine. for example the KX 91 shares the same quick disconnect system as the KX 71 and maybe the KX 121. These however are differ than say a Bobcat machine. It is not standardized like the skid steer QD system.
I found there are a lot of good Bucket manufacturers out there on the market, if you look around you can find some deals and drive the costs down while still getting a HD quality bucket.

MinnesotaEric · Jan 24, 2017

With HD reaching in from China, I've a new Sany dealer in MN. Anybody know anything about their 8 ton excavator?

http://www.sanyglobal.com/handbook/SY35U.pdf

Here is their company demo vid.