Here is a picture of my RTV1100 2009, which should be close to the 1140 if not the same.
After having the Kubota techs adjust neutral, arrow points to aluminum block which has the allen head screw with lock nut, it is hidden in this shot behind the hose coming from the HST filter, I then adjusted the HST rod pictured here with the red wire tie.
By the way, neutral is adjusted by installing 2 pressure gauges into the block at the rear of the transmission, one is by the suction (red) filter and the other on the opposite side. They adjust the neutral screw until both pressures read equal amounts. Mine was off quite a bit.
Now the HST rod. If you look closely in this photo, you will actually see the lock nut is loose. I was making adjustments. One lock nut is 12mm and the other end is 13mm. Loosen both and then turn the rod itself. Be careful, one is LEFT hand thread.
The procedure is (everything shut off, of course)
1 remove the lock nut/washer from the HST rod end that holds it to the servo arm, black painted cast iron item with arm attached to shaft
2 manually move the servo arm ahead as far as it will go and mark the case
3 re-attach rod and arm
4 have someone slowly press the accelerator pedal all the way to the floor
5 now check that the servo arm is 1mm back from the mark you made on the case. If not adjust the rod until it is and then re-tighten the lock nuts.
The idea, as I see it, is that when press the pedal to the floor and the engine is at full speed, both the engine speed and arm movement should reach maximum at the same time or be in sync. The 1mm of clearance is so the little shift fork inside is not applying constant pressure at full throttle or has a little wiggle room and will not wear out from the constant pressure.
It is hard to be exact with the 1mm less full travel on the servo arm so I actually used a dial gauge on mine. Took some time but was worth the effort to know it was exactly to their specs.
These two items made the biggest difference to my shifting.
You still need to stop and shift into all ranges, Low Med High Reverse,
because the brake actuates the pressure relief, so press hard on the brake wait 2 seconds and then shift.
Before doing this procedure you should try shifting as described and if it is easier, I would suggest not doing the procedure.
Or save you money and because you said you are mechanically inclined just check the servo arm/hst rod adjustment.
