RTVX1140 Power

[Maxman]

I purchased new RTVX 1140 in summer of 2016. Used on hunting property, so only have 100 hours on it. I bought as a work vehicle not a thrill ride. That said, I'm very disappointed in the low range power. My property is a decent hill with some pretty steep pitches. I'm always running in 4x4 Low Range. I noticed during the first year that the unit would bog down when climbing with load 4 people. I thought it was strange but "lived" with it. This year with a bunch of big boys, the unit stalled. I immediately started it up and it crawled right up. After spending $19,000, I ain't happy with this performance. The fact that I immediately restarted and it climbed right up, I'm wondering if I have a pump issue. Perhaps it left the factory not calibrated correctly. Anyone out there experiencing similar issues? I need to take it in to have them look at it, but just wondering if others are seeing same performance issues.

 

[RCW]

Max -

I'm of no help, but there are a few guys on here with RTV's.

There are also some guys on here that are experienced mechanics, and may be able to offer some advice specific to your 1140.

My first thought was fuel related....do you use any additives in your fuel, and have your filters been changed? Diesel can attract water, algae, and junk in general to gum up the works....

Not familiar with your 1140, but smaller tractors (BX) have 2 plastic filters that are transluesent. One filter is near tank, and other is after a "lift" pump, near the injection pump (IP) on a BX.

Any discoloration in the filters if similar?

EDIT: Max -- you have one fuel filter, and your lift pump is at the engine before the IP.

Go here:

https://apps.kubotausa.com/illustrated-parts/

Agree to the terms, and put in your model#. Go to "Fuel System" and you can see parts diagrams and part #'s.

I might start with a new filter, if not done already.

 

[eserv]

The fact that you were able to start the machine then power on up the hill convinces me that there is nothing internally wrong with your transmission.
When you press down on the accelerator on any Kubota rtv you are not only advancing the throttle but also effectively shifting the Hydro into a progressively higher gear. this is why they will often go up a steep hill better at half or less throttle than if you just floor it.
That being said though, your machine will likely benefit with less charge pressure than the factory setting especially if you regularly carry 4 "big guys ! Late models have an external adjustment for charge pressure, earlier ones do not.
Make sure the linkage is actually pulling the engine to full throttle, many come from the factory not quite adjusted properly.

 

[lugbolt]

The fact that you were able to start the machine then power on up the hill convinces me that there is nothing internally wrong with your transmission.
When you press down on the accelerator on any Kubota rtv you are not only advancing the throttle but also effectively shifting the Hydro into a progressively higher gear. this is why they will often go up a steep hill better at half or less throttle than if you just floor it.
That being said though, your machine will likely benefit with less charge pressure than the factory setting especially if you regularly carry 4 "big guys ! Late models have an external adjustment for charge pressure, earlier ones do not.
Make sure the linkage is actually pulling the engine to full throttle, many come from the factory not quite adjusted properly.

I agree-well mostly. The charge pressure is likely on the higher end of the specification (probably in the 110 psi range if I had to guess), and that'll make the engine bog and possibly die-especially if the transmission fluid temperature is not at operating temp. That in itself is THE reason that the HST is not an ideal transmission for this type vehicle. The HST's characteristics WILL change with temperature, the hotter the fluid the more "slippage" it will have. And on that note, setting it at around 99 psi seems to be the best compromise, it'll still be real sluggish when cold, but it will loosen up nicely when it warms up. Much lower (like down to about 90 psi), the trans will "slip" more when cold, but will slip a LOT more when hot, to the point where the top speed will fall off quite a bit and it'll just be real sluggish-or more specifically considerably more sluggish than it is now....

On fluid, it MUST have super UDT2 in it, nothing else. It's the only fluid that works acceptably well in an HST, especially in a side-by-side. If it's got any hours on it and has been used in the heat a lot, it's advisable to change the fluid and filters. While on the maintenance stuff, also many tend to forget that the air filter on diesels will plug faster than a gas burner and it'll also cause a power loss. AND...look at the spark arrestor...when it gets dirty, it'll also cause a power loss. Worth mentioning.

And finally, keep in mind that the little engine makes around 24 horsepower and the machine weighs around 2000 lbs. Add 4 grown men (what? 800 lbs) and you have a total slug in every possible way. It ain't ever gonna be a powerhouse, but in low gear it SHOULD pull a load up a slight grade. "Slight" being subjective. Had one RTV customer tell me that he had a small hill to go up behind his house. I get there to inspect his machine and the terrain it's used in; and I am not sure I could have got up it with a ladder.....I think "cliff" would have been a better description, and the guy couldn't understand why his RTV wouldn't go up it.

Good luck...if you don't mind, keep us up to date if you can.

 

[eserv]

I agree-well mostly. The charge pressure is likely on the higher end of the specification (probably in the 110 psi range if I had to guess), and that'll make the engine bog and possibly die-especially if the transmission fluid temperature is not at operating temp. That in itself is THE reason that the HST is not an ideal transmission for this type vehicle. The HST's characteristics WILL change with temperature, the hotter the fluid the more "slippage" it will have. And on that note, setting it at around 99 psi seems to be the best compromise, it'll still be real sluggish when cold, but it will loosen up nicely when it warms up. Much lower (like down to about 90 psi), the trans will "slip" more when cold, but will slip a LOT more when hot, to the point where the top speed will fall off quite a bit and it'll just be real sluggish-or more specifically considerably more sluggish than it is now....

On fluid, it MUST have super UDT2 in it, nothing else. It's the only fluid that works acceptably well in an HST, especially in a side-by-side. If it's got any hours on it and has been used in the heat a lot, it's advisable to change the fluid and filters. While on the maintenance stuff, also many tend to forget that the air filter on diesels will plug faster than a gas burner and it'll also cause a power loss. AND...look at the spark arrestor...when it gets dirty, it'll also cause a power loss. Worth mentioning.

And finally, keep in mind that the little engine makes around 24 horsepower and the machine weighs around 2000 lbs. Add 4 grown men (what? 800 lbs) and you have a total slug in every possible way. It ain't ever gonna be a powerhouse, but in low gear it SHOULD pull a load up a slight grade. "Slight" being subjective. Had one RTV customer tell me that he had a small hill to go up behind his house. I get there to inspect his machine and the terrain it's used in; and I am not sure I could have got up it with a ladder.....I think "cliff" would have been a better description, and the guy couldn't understand why his RTV wouldn't go up it.

Good luck...if you don't mind, keep us up to date if you can.

Well I certainly agree that an HST is a poor choice for a RTV type vehicle! Add to this that it is seriously underpowered for it's weight....... then people add a big cab and windshield to these vehicles and want to carry 4 people plus cargo in the back. But in the end with careful adjustment and reasonable customer expectations they can work pretty good!

 

[Saxman]

Who had experience with using the Kubota hand throttle to hold the engine at max RPM and using the accelerator pedal like the hydro peddle on our tractors. I have read something about this on other forums. I just traded my RTV500 for a 1120D and I’m thinking about adding the hand throttle


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[eserv]

Who had experience with using the Kubota hand throttle to hold the engine at max RPM and using the accelerator pedal like the hydro peddle on our tractors. I have read something about this on other forums. I just traded my RTV500 for a 1120D and I’m thinking about adding the hand throttle


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I've suggested that to some customers, haven't heard back how it works out for them
Your new 1120D is a totally new HST that incorporates a variable displacement pump AND a variable displacement motor. They are working much better than the old system!

 

[Saxman]

I haven’t had time to play with it much since it’s been so cold. I can tell it has a huge amount of torque. Grades that the little 500 had to be in low range to climb can be handled at idle in high range in the 1120. I know this is apples/oranges comparison but I can tell a huge difference

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[footloose64]

Maxman, and Saxman, by all means get the hand throttle. It makes all the difference in the world. You WILL realize you bought the right machine for heavy hauling. Our dealer recommended it when he found out our land was steep. We haul probably 1500 pounds of 4' logs plus the two of us, up very steep hills, so steep the wife had to get out on the hood once to make sure we didn't flip over backwards! No problem with enough power though. Just keep the peddle light so you stay in low (hydraulic) gear. You're not going to believe what you've been missing. Don't go crazy though, and flip over backward, OK? Can probably easily install it yourself if you get the cable from the dealer. Ours is mounted on the horizontal panel to the left of the driver's seat, near the dump control.

 

[Saxman]

Thanks Footloose, I have it installed and really like it. Not tried pulling much yet I’m sure it will be as you described.


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