</font><font color="blue" class="small">( Brad, when I go light on the throttle I am not getting all the horse power to the wheels unless I put my foot into it. )</font>
George,
By light on the pedal, I meant the hydro pedal. Running wide open throttle with only pushing the hydro pedal down 1/4 of the way or even less, that should be the most power. Most of the time mine will spin, but under good traction conditions, even just touching the pedal will not spin the tires, indicating to me the relief valve as kicked in. It does not lug the engine much during this slipping. At that point if I push the pedal all the way down, of course it lugs down and eventually stalls. But that is the same as taking a geared machine to its limit in low gear, and when it doesn't go, shifting to a higher gear and dumping the clutch. Again, it's going to stall.
I would be interested to hear what happens on your machine if you try just lightly touching the hydro pedal in low range, forward or reverse, under heavy load such as a steep hill where you usually can lug or stall. It won't go fast, but I'll bet it goes. I've never stopped my wheels pulling a heavy load. The only time was pushing into an immovable object such as a pile of frozen snow.
Brad