RTV HST Adjustments

rakinnear

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Ok thanks I will test it and see what I come up with. I used Harvest King brand hydraulic fluid which is called out as Super UDT fluid. The manual I have calls for Super UDT should I be using Super UDT 2 instead?
 

aurthuritis

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ok. i highly recommend that you change the fluid to SUDT2 and use oem filters also before you adjust anything. this alone could be your only problem. these RTV are very finiky about the trans fluid. the off brand filters sometimes restrict flow and cause issues also. this is why in any of these threads the first question is "what fluid did you use?".
 

rakinnear

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Got it, thank you! I did use all Kubota brand filters and only used harvest king for the fluid but I will pick up some kubota udt 2 and change the fluid
 

aurthuritis

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i hope this solves any issues for you. please let us know the results? don't forget the tank under the seat.
 

aurthuritis

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something to note....my 2007 rtv 1100 in high will get about 27 mph on rolling ground dirt roads. and drops to about 19 mph on about a 6 percent grade. but for power i need to drop to medium or low. it is often in soft ground or climbing from stop in high that the machine will stall.
 

rakinnear

New member
something to note....my 2007 rtv 1100 in high will get about 27 mph on rolling ground dirt roads. and drops to about 19 mph on about a 6 percent grade. but for power i need to drop to medium or low. it is often in soft ground or climbing from stop in high that the machine will stall.
Thanks! It seems to hold speed pretty well on relatively flat ground. I primarily run it in Medium due to the hills we have and will often have it where it begins climbing well if i start at a decent speed but feels like it continues to drop power as it climbs
 

aurthuritis

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depends on what you call a hill? but really that doesn't sound to far from normal. one thing you can do on that model especially is use the hand throttle to rev the engine to max and then just use the peddle for speed control in the tough stuff.
 

rakinnear

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depends on what you call a hill? but really that doesn't sound to far from normal. one thing you can do on that model especially is use the hand throttle to rev the engine to max and then just use the peddle for speed control in the tough stuff.
Ill admit the drive is pretty steep. Is the hand throttle different that the high idle control?
 

aurthuritis

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you can use that high idle control but you have to hold it up or it will auto return. kubota makes a hand throttle kit for the rtv that works like a tractor throttle. but you can sure test the results with what you have so you can see if it is worth spending on a throttle kit,
 
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geohorn

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One of the major design oversights Kubota commits in my opinion is the lack of tachometer readout on the dash of these things.
I’ve tried a couple aftermarket devices and they all sucked and I returned them.
 
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aurthuritis

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i agree. i have a professional multi tach that has a photo head and also a clip on the injector line pick up and a few others. i was hoping the cheap laser tachs were good? the little engine can handle many more revs i learned from the guys who soup them up for pulling contests but the HST can't handle much over 3800 rpm. also though the smoke screw adjustment won't do much good unless the governor calls for more rpm.
 

v10rick

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One of the major design oversights Kubota commits in my opinion is the lack of tachometer readout on the dash of these things.
I’ve tried a couple aftermarket devices and they all sucked and I returned
My BX2350, with a similar engine to the RTV, is equipped with a digital engine Tach. A forum search mentions that the BX rpms are sensed from the alternator. Wonder if this could work...
 
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ItBmine

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i hope this solves any issues for you. please let us know the results? don't forget the tank under the seat.
YES!! Drain the hydraulic tank under the seat also. The owners manual does not tell you to do this. I thought it was a separate system for the dump and power steering, but when I drained the transmission and pulled the filter off, imagine my surprise when a gallon of oil poured out all over my driveway, LOL
 

rakinnear

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Sorry for they delay! Im going to change the fluids this week.

I was going over a few other things this week and removed the skid plates which had definitely served there purpose and noticed one of the hydraulic cooler lines had been pinched by the skid plate. So I ordered a new coolant line and was waiting for it to arrive so I could do everything at once.
 
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rakinnear

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Sorry again for the delay. I was able to change all the hydraulic fluid and filters and also replace the coolant line running from the hydraulic filter to the block (it had been pinched by the skid plates)

overall it does feel like its running and shifting a little better but I havent noticed and significant power differences in making it up the hills we have around here.

would you have any other recommendations? Spark arrestor has been cleaned and is clear.
 

aurthuritis

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please describe Hill? percent of grade and length from bottom to top? gear selection speed at bottom of hill and peddle position and speed at top of hill and peddle position?
 

rakinnear

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The hill is about 1/10 mile long and i keep it in Medium. I will start out coming down a small grade in front of it at full throttle and will hold around 15 mph at the beginning of the hill but drop to about 7mph by the top of it. Im not sure of the grade it is a driveway but fairly steep. My farm tractor does hold a fairly consistent speed going up it in medium for comparison
 
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