On my CK20HST I find that anything over 2,000 rpms for backhoe work makes it too twitchy and swings to fast, I run it at about 1,900-2,000 rpms. For loader work, I run about 2,200-2,500 rpms so the engine does not bog down at all when I am curling/lifting the bucket while driving into a pile and steering all at the same time.