B6100 HST D Struggling with 3-pt mower

[swierczt]

I have a Kubota B6100 HST-D That I recently attached a 4-foot rear mount mower. The tractor runs fine, however, when I try to mow up hill, she really struggles. I have a 5' brushog (that I know is too big for this tractor) and we can cut light stuff up hill and down all day just fine....it seems to really have a hard time with this little RMM. Works fine on flat and down hill..just on the up hills. All 3 blades spin easily as well as the drive shaft. I can go up hill just fine so long as the pto is not engaged to run the mower. Recently changed the oil in the motor, all hyd. fluids seem ok....anything else I should look at? Thank you!

 

[Thomas]

I had 3pt hitch mower on my X B7100HST.
Going up hill while mowing I had to use low range and feather hst pedal..while useing rear pto hst has less hp to offer than gear tranny.

Wet thick green grass etc. I found out slower speed,higher setting,2/3 deck cut instead of full deck.

 

[dodge man]

Whats the HP of your tractor, something like 16? I think the rule of thumb is 5 horsepower per foot of mower, so you should have something like 25 for a 5 foot mower. I'd say its having problems because the mower is too big.

 

[zoltanthegypsy]

You may just have too much mower (I have no clue) but I recently had a similar issue with my little BX24. Mow on the flat all day, severe RPM drop on a hill unless I crept up.

Replaced both fuel filters, and it's fine now. Fuel starvation, presumably.

Z.

 

[BrierPatch]

Honstly, I never really thought about this, but I would have suspected that the brush hog would take more power to run, just because it seems like it can do harder work. My thoughts would be that the 5' brush hog has a gear reduction on it because we don't need the spindle speed because of the longer cutting blades. Think in terms of blade tip speed. However, I would think that a finish mower doesn't have a gear reduction or possibly a gear increase, which means less power/torque. The finish mower with 3 smaller blades needs to spin faster to get the blade tip speed, which should be faster than a brush hog, because of the function "finish mower" not "hack and slash" mower. Plus, brush hogs are ran at the 540 pto speed. Think of this, the more gear reduction, the more torque you have or it is easier on the tractor and the less gear reduction/increase makes it harder on the tractor to provide the same torque. Does your tractor have a 2 speed rear pto? Both of my Kubotas have/had 2 speed pto's and the MMM always runs at the higher speed setting, but 540 for the brush hog. You may just be getting to the limits of your tractors hp, even though we naturally consider the finish mowing the easier task. Maybe this is why we hear all time of people putting larger than recommended brush hogs on the tractors and saying it works fine for them just like you. The larger size limit may not be based off of power, but physical size and weight since they have gear reducers on them and the tractors are able to spin them.

Don't know, just my thoughts, Good Luck!

 

[swierczt]

Thanks for all the input.

The tractor does have a 2-speed PTO and manual says to run the mower at 540 RPM. I was thinking that maybe the brush hog works well because once the big 'ole blades start spinning, they don't require as much hp from the tractor to do their job. I was wondering if I should take a look at the hyd. strainer...I purchased the tractor used so don't know if this was ever done....I've checked the hyd. fluid level (looks clear, always at the correct level), that's about it. The machine always ran fine and as the old saying goes if it ain't broke don't fix it. I've changed oil and filter at prescribed intervals and changed the fuel filter and the air filter. I just don't want to kill the old girl mowing the lawn.

 

[BrierPatch]

Might be a good idea to change the hst filter and clean the hyd. screens. I've seen on hear, several times, where the hyd. screen doesn't get much attention and needs cleaned and has made improvements.

Good Luck !

 

[swierczt]

Might be a good idea to change the hst filter and clean the hyd. screens. I've seen on hear, several times, where the hyd. screen doesn't get much attention and needs cleaned and has made improvements.

Good Luck !

Do you know if there is a procedure for this or where the screen is located? I have two different part manuals and both show something different???

 

[KubotainNH]

I was thinking that maybe the brush hog works well because once the big 'ole blades start spinning, they don't require as much hp from the tractor to do their job. I was wondering if I should take a look at the hyd. strainer...

I think this is it on the nose. You have inertia on your side because of the weight kinda like how a chipper works. The mower has 3 lightweight blades cutting what may be thick/wet grass, that takes some power. All these little tractors have is 12HP at the PTO. Maybe adjust your mowing strategy and keep your blades sharp. Higher engine RPM's on the uphill if possible.

As for the strainer, I believe it's attached to the bolt that goes through the metal banjo fitting under the seat. The metal line goes straight to the pump on the motor.