BX2660 MMM belt wants to climb up left pulley

dodge man · Jul 1, 2016

One thing I've noticed is if you don' run the mower at or near full throttle, there will be certain RPM's that make the belt vibrate badly. I don't know if this could be your problem or not.

nepa · Jul 1, 2016

I would be disappointed in Kubota if that were the problem. My Case does everything I need at no higher than 1800 rpm. My 28hp Jinma maxes at 2400 with exceptional power and I only need that power to speed up cutting 70 acres of hay. It jangles my nerves to hear the Kubota screaming at 3200 so I try to keep it at the 2900 area. This is an awfully expensive machine to have quirks about rpm below full throttle.

TMGT · Jul 2, 2016

nepa said:
I would be disappointed in Kubota if that were the problem. My Case does everything I need at no higher than 1800 rpm. My 28hp Jinma maxes at 2400 with exceptional power and I only need that power to speed up cutting 70 acres of hay. It jangles my nerves to hear the Kubota screaming at 3200 so I try to keep it at the 2900 area. This is an awfully expensive machine to have quirks about rpm below full throttle.

It would be a harmonics issue if that is the case, not a Kubota thing.

I had a mower that didn't like certain rpm, belt would move around and hit part of the deck reinforcement, I didn't mow at speeds below full throttle just noticed it one day when I throttled it down to disengage the blades. This was a comercial mower.

The Kubota's are designed to run those rpm, doesn't help to run it lower really.

nepa · Jul 2, 2016

I hate to change subject in my own thread, but it leads me to a different issue that I have with the Kubota. My Jinma idles at 600 rpm vs 1300+ for the Kubota. I drive my Jinma on my drive way at 1200 rpm (without lugging) and my ground speed is greater than the Kubota at full throttle and hydro all the way down. The FEL on my Jinma scoops, lifts, and dumps faster at 600 rpm idle speed than the Kubota at 3200 rpm. I usually use the Jinma FEL at 1800 rpm while lifting greater weights and volumes than the Kubota is able to handle. Now I am finding that I should be cutting grass at 3200 rpm where I pull a 72 inch finish mower behind the Jinma at 2000 rpm with greater ground speed. My questions are: If I am putting over twice the revolutions on the Kubota engine will this take a toll on engine life? Should maintenance be performed more frequently? Do I burn more fuel to do the same job relative to the Jinma?

I love how easy it is to remove the FEL from the Kubota because it gives much better maneuverability around obstacles. I also love the control that the wide tires, low profile, and the hydro trans give me while mowing steep slopes. But, I switch over to the Jinma asap because it gets the work done faster and the seat, which is mounted on an adjustable tension spring with shock absorber inside (which I sure wish the Kubota had), is greatly more comfortable to sit in.

dodge man · Jul 2, 2016

They are designed to run that rpm. I know that seems fast, but I mow with mine wide open. I think it's a misnomer that you are "using up" the engine spinning it that fast. When I'm using the end loader and other work I tend to run it at 2800 rpms or lower.

TMGT · Jul 2, 2016

Your comparing apples to oranges with the two tractors. That would be like me comparing my old 93 toyota pickup to my 2500 dodge.

The hydraulics only use a single pump with a priority valve for the sreering, all additional flow goes to the implements so if the speed/flow is lower you'll notice it.

As Dodge man said, the Kubota is designed to run at higher rpm. I have 2 kubota powered mowers, one has a similar sized engine to yours and the other has a larger engine, both spent their life on a golf course and ran full rpm the whole time, one has 4000hrs and the other has 3600hrs. Both run great with no smoke or issues.
I wouldn't be worried about engine life running at the rated rpm.

As for maintenance, just go off Kubota recommendation in the manual, It's based on how the tractor should be operated.