Kubota RTV900 lack of power

[DT86]

dirt for sure

There won't be any of that here for another month.

 

[murphyzoo]

I adjusted the servo screw today (total of 3 turns in). I didn't notice any difference in power output to the wheels (wouldn't spin on dirt in L gear).
I did notice that after the 3rd turn-in, when I let my foot off the throttle, the RTV started moving backwards. I put the screw back to the original setting.

 

[daviki44]

I'm having trouble with a new-to-me 2005 Kubota RTV 900. It seems quite under-powered. I'm well aware that this diesel RTV is meant as a work-horse and not a speed demon. Our main goal with this is to be able to drag our horse arena with the ABI Arena Rascal Pro. The drag is built so that a 750cc ATV should be able to tow it. The ABI company said that a RTV900 should be more than sufficient.

The engine appears to run ok - it revs up and sounds smooth, but just feels underpowered. We have a slight hill on our property and the RTV has a hard time going up it in M and sometimes in L. If we stop on the hill, it's near impossible to get going again. Under load (towing the arena drag), it is very apparent the RTV doesn't have the power it should - we know it isn't a tractor and aren't trying to do something an ATV couldn't do. We also seem to notice that it loses even more power when it fully warms up. I'll drive it down our street in H gear and use a GPS to measure the speed. Once warm, the speed will be 3-4mph slower (this seems odd to me).

We picked it up with about 2400 hours on it. I did a full fluid change using Kubota SuperUDT2 and Kubota brand filters. I added a high-rise air intake and have checked the exhaust spark arrestor. I also added the hand-throttle option based on my local dealer's recommendation so that I can rev up the engine separate from driving the transmission. I've read several of the articles on RTV's with low power, so I know not to just mash the throttle to the floor. With the break off and the RTV in neutral, it rolls smoothly, so I don't think the brakes are an issue.

What else should I check on this RTV? Would you guess this to be an engine power issue or a transmission problem getting the power to the wheels? What's the best way to find out where the issues are?

Thanks

Hi read your post many years ago, having the same problem, I was wondering if you had success figuring it out. did you take to dealer. Reading it was like a cliff hanger without the last page. Thanks so much for any answers you have.

 

[murphyzoo]

I ended up taking the RTV 900 to a Kubota dealer for service and found that the hydrostatic drive needed to be rebuilt. They replaced several components related to the hydraulic pumps in the hydrostatic drive (just over $2500 worth after labor / taxes / etc.). It ran like a champ after that. (well, until I let the radiator clog up with dirt and overheated the engine - that's another post though).

I was hoping for a cheaper solution, but this was the right thing to do. All the power issues were resolved after the hydrostatic transmission rebuild.

 

[daviki44]

Thank you murphyzoo for such a quick response. no I did not enjoy your answer, lol. being ours has under 350 hrs. I will also Hope for a different outcome. Thanks again