Mowing Kubota B2650 not enough power for FDR2572 mower?

[MossRoad]

No, it could make it in mid range by dramatically slowing down to the point of barely moving in mid range, in low range without the loader you could stay at full HST and the PTO RPM would drop to around 400.

I know that. I also know that you are familiar with how to let off the HST pedal to get more response when the machine starts to bog down. I have to do that with my HST machine as well.

What I'm curious about is that I would think that if you had to let off the HST pedal in M range to get it up the hill fully equipped, by just shifting into L range, it should have walked right up the hill fully equipped. By shifting into L it should have increased your effective gearing by about 32%. That's a huge number. Even with the oversized tires, it should have been a significant change in effective gearing switching from M to L. That's the part I'm having a hard time understanding.

On the overall issues, I'm guessing that by putting oversized tires on it, and a mower deck that is probably at the hairy edge of too large for the input PTO HP of 19.5, coupled with your hill slope, the machine is going to be underpowered.

Your engine is rated at 26HP, your PTO is using up to 19.5HP if you load the mower down with air resistance and grass blades, that only leaves you with 6.5 HP to move it up the hill. Add to that the 7% gear reduction of the taller tires.

So much for someone else's assumption that raw machine weight is more important than engine HP. When doing tasks like mowing, engine HP is extremely important, more imortant than machine weight, because it has to be able to spin and keep spinning the mower through varying resistances of wind and grass/brush, while at the same time moving the machine on varying terrain both up and down.

I'm not criticizing your machine or decisions, but it sure is coming acrosss that way in my written text, so please don't take it that way. I'm not the most eloquent writer. I wish we could sit around a fire pit or the garage with some other TBN folks and talk about it with some beverages. My own machine has some shortcomings that I'm happy to pick apart as well.

Good luck with the diagnosis and cure.

 

[SDT]

If you opt out of that mower, let me know what the deal offered to you is. I may be interested... I'd like to get one to see if I could reshape it enough to make it fit with my tires. The thought of swapping around 500 pound tires is not at all appealing to me. I have around 400 lb of Rim Gard, plus the weight of the tire that is (guessing) around 100 lbs and the weight of the wheel that has to be 50+ lbs. My 37x13.50 Jeep wheels and tires are around 120 lbs each and I don't overly enjoy rotating those...

Neither one of us will get the 72" mower.

I learned from my dealer today that Kubota wants it back.

SDT

 

[Rock Crawler]

I know that. I also know that you are familiar with how to let off the HST pedal to get more response when the machine starts to bog down. I have to do that with my HST machine as well.

What I'm curious about is that I would think that if you had to let off the HST pedal in M range to get it up the hill fully equipped, by just shifting into L range, it should have walked right up the hill fully equipped. By shifting into L it should have increased your effective gearing by about 32%. That's a huge number. Even with the oversized tires, it should have been a significant change in effective gearing switching from M to L. That's the part I'm having a hard time understanding.

On the overall issues, I'm guessing that by putting oversized tires on it, and a mower deck that is probably at the hairy edge of too large for the input PTO HP of 19.5, coupled with your hill slope, the machine is going to be underpowered.

Your engine is rated at 26HP, your PTO is using up to 19.5HP if you load the mower down with air resistance and grass blades, that only leaves you with 6.5 HP to move it up the hill. Add to that the 7% gear reduction of the taller tires.

So much for someone else's assumption that raw machine weight is more important than engine HP. When doing tasks like mowing, engine HP is extremely important, more imortant than machine weight, because it has to be able to spin and keep spinning the mower through varying resistances of wind and grass/brush, while at the same time moving the machine on varying terrain both up and down.

I'm not criticizing your machine or decisions, but it sure is coming acrosss that way in my written text, so please don't take it that way. I'm not the most eloquent writer. I wish we could sit around a fire pit or the garage with some other TBN folks and talk about it with some beverages. My own machine has some shortcomings that I'm happy to pick apart as well.

Good luck with the diagnosis and cure.

I'm learning also that that verbose individual see life and tractors through a very narrow view.

 

[MossRoad]

I'm learning also that that verbose individual see life and tractors through a very narrow view.

OK. Straight to the point.... why's it such a dog in low range?

 

[Rock Crawler]

Lack of horsepower obviously. You have a finite amount of power output to spread around. While I have more than enough weight to do any job that this size machine could be asked to do, I do not have the required horsepower.

The number one consideration for buying a tractor is horsepower. After you get that settled, consider how much weight you want to buy to do what you want.

 

[MossRoad]

When I was researching machines back in 2001 to get for our needs, and after discussing it with the factory several times, they convinced me to get the highest HP model they made for that frame size so I could spin the 60" mower deck that I wanted, and still climb moderate hills. However, they warned me that if I had extreme hills to get the 48" mower or I may have to turn the mower off going up the hills. I've only run into that a couple times with the 60" deck, and just modified my route to go up less-steep slopes and only come down or across the steepest ones. I have had to turn off the 48" brush cutter on my steepest hills, but those are exceeding 20 degrees, probably closer to 30, and I shouldn't operate on anything over 25 for extended periods with my lubrication system.

 

[SDT]

I run the wheel and tire package that is optional when buying the B3350SU.
According to a Kubota engineer response, it costs me 7.?? Percent of the designed gear reduction.

But, it adds a lot more fluid fill weight for my hills, it takes my width to 60.5" in the rear, it gives more aggressive tread design and it has much greater surface area... So it has at the least, equal or possibly less ground pressure per square inch to allow for less damage the grass.

Oh, and it looks cool as heck View attachment 550173View attachment 550174View attachment 550175View attachment 550176

Do you know if the oversized front tires interfere with the turning radius? Sometimes oversized tires require resetting of the steering stops to prevent interference between the tires and whatever at full lock.

Also, do the oversized rear tires preclude the use of tire chains?

If either is the case, I will go back to the standard sized tires on my B3350, which will not be delivered for awhile.

Thanks in advance.

SDT

 

[Rock Crawler]

Do you know if the oversized front tires interfere with the turning radius? Sometimes oversized tires require resetting of the steering stops to prevent interference between the tires and whatever at full lock.

Also, do the oversized rear tires preclude the use of tire chains?

If either is the case, I will go back to the standard sized tires on my B3350, which will not be delivered for awhile.

Thanks in advance.

SDT

The inside edge of the oversized tires from the B3350SU is at the same location as the standard wheel/tire, the wheel ring on the wider tires/wheels is shifted outwards from the hub mounting surface to place the inside edge back to where it is with the smaller wheel and tire. You'll need spacers for the chains on the B2650/B3350/B3350SU but I am going to assume that if you are looking at getting the bigger tire package, then like me you are looking at adding width for stability. If your doing that, you are most likely ordering the $399 Kubota 1.5" wheel spacers as well that will set your rear axle at 60" track width. In that case, the chains are not an issue. The question to ask is more like: Who has chains on a B3350SU with the optional larger tire package? That would get you the information your looking for as far as how tight things are in that configuration. I know that you need the spacers without a doubt. You can also price out 2" Brotek spacers, they may be cheaper than the 1.5" Kubota spacers, I never really looked. I had mine ordered as I wanted from Kubota to the dealer, so everything is "clean" from a warranty standpoint. My dealer initially was going to take an in-stock B2650 and merge it with tires for an in-stock B3350SU but decided to just make a clean/new order for my B2650 to ship in as I wanted so that he was not stuck sitting on a set of smaller wheels and tires that he did not want to be holding.

With the wheel/tire upgrade, you get a new/different front axle hard stop for the knuckles that keeps your larger front tires from hitting the frame. It still turns sharp, sharper than you would want in your grass because the wheels turn so far that they start to "plow" and "push" and tear up grass at full lock. I work in tight trails a good deal, and the turning radius is the least of my worries. Non issue.

 

[SDT]

The inside edge of the oversized tires from the B3350SU is at the same location as the standard wheel/tire, the wheel ring on the wider tires/wheels is shifted outwards from the hub mounting surface to place the inside edge back to where it is with the smaller wheel and tire. You'll need spacers for the chains on the B2650/B3350/B3350SU but I am going to assume that if you are looking at getting the bigger tire package, then like me you are looking at adding width for stability. If your doing that, you are most likely ordering the $399 Kubota 1.5" wheel spacers as well that will set your rear axle at 60" track width. In that case, the chains are not an issue. The question to ask is more like: Who has chains on a B3350SU with the optional larger tire package? That would get you the information your looking for as far as how tight things are in that configuration. I know that you need the spacers without a doubt. You can also price out 2" Brotek spacers, they may be cheaper than the 1.5" Kubota spacers, I never really looked. I had mine ordered as I wanted from Kubota to the dealer, so everything is "clean" from a warranty standpoint. My dealer initially was going to take an in-stock B2650 and merge it with tires for an in-stock B3350SU but decided to just make a clean/new order for my B2650 to ship in as I wanted so that he was not stuck sitting on a set of smaller wheels and tires that he did not want to be holding.

With the wheel/tire upgrade, you get a new/different front axle hard stop for the knuckles that keeps your larger front tires from hitting the frame. It still turns sharp, sharper than you would want in your grass because the wheels turn so far that they start to "plow" and "push" and tear up grass at full lock. I work in tight trails a good deal, and the turning radius is the least of my worries. Non issue.

Thanks for the information.

I'm not particularly interested in stability so will not use wheel spacers but will likely need chains for plowing snow. I also do not wish to interfere with turning radius so I think I'll revert back to the standard R-4s and save a few dollars in the process.

SDT

 

[davidcbaker]

I haven't read all each post, here, so sorry if I missed where someone else might have suggested this. I agree that it seems underpowered, but is there an obstruction in the air filter? It would feel that way.