There were a couple of threads on this very subject a while back. The rachet on the throttle is a pain. The solution that worked the best for me was to open the TX back and put a piece of silicon fuel tubing over the metal arm that contacts the plastic rachet. I tried taking the metal metal arm out but didn't like the totally loose throttle. Also tried other kinds of tubing but the silicon has the right slipperiness, heat shrink sticks.

When I asked the ace pilot at the LHS about it he said that you really have to fly the throttle full time. A smooth throttle makes it a lot easier.