Kubota RTV x900 and the Power Trac

[woodlandfarms]

So a simple story to tell, we recently scored on one of these little diesel side by sides. Great machine. Still getting used to it. One thing is that it is a Hydrostatic Transmission so the more you mush on the pedal the less likely you are going to get up that steep hill.

So many people returning these machines over this issue. Just let off the pedal, its how it is supposed to work. Well, actually their is a wierd design flaw in that the gas pedal is tied to the carb as well as the Hydro Tranny. I just bought a kit to seperate the two.

In the end i had no issues getting up the hill, thought it was normal.

 

[MossRoad]

There's been discussions a few times on here about throttle speed and hydrostatic drives. My old IH2500b operators manual specifically stated to operate the machine at PTO RPM or higher to insure proper operating pressure, hydrostatic cooling, and wheel braking, to name a few. I was discussing this with TBN member Mark Chalkley about his Earth Force machine. He said he had a valve /device installed (or the machine came with the valve, I can't remember, it was over 15 years ago). The valve/device would sense hydrostatic demand and ramp up the throttle based on that demand in coordination with the directional pedals. The pedals weren't throttle pedals, they were still directional pedals. It was just that the machine could sense how much throttle to add based on the hydrostatic load. He said it saved him a ton of fuel and most likely would add to engine and drive component life. I think the valve/device was made by Rexroth.

I have no idea how your Deutz engines would fare with such a device and how they rely on flow for the oil cooling. I know my Kohler is meant to run at a higher RPM under load for air cooling. And my hydraulics are not nearly as responsive at lower RPMs. But I'd still be interested if something could be fitted to the Deutz powered machines to save fuel and noise.

 

[ponytug]

I think that the challenge for the PT Deutz engines is that you would need pressure/flow monitors on both the PTO pump circuit, and both sides of the wheel motor pump to account for forward and reverse loads.

I can see how to do that digitally, but not with a pressure controlled analog circuit.

A risk that you might run, is not getting the engines warm enough in intermittent use. One thing that comes up with variable speed diesel generators is “wet stacking”, when the engines never make to WOT to decarbonize the engine and exhaust system. It can cause a lot of damage quickly. You can see a lot of military surplus generators, with low hours, that basically need a rebuild, because of the coke in the cylinders.

All the best,

Peter