Moondog,
Mine had a sticky throttle as well. But she had been sitting for 9 years! I disassembled the mechanism at the grip, cleaned it, greased it (lightly!) and it eventually worked itself back to normal operating mode (especially when we got out of the freezing temperatures up here in the North!). Give it a shot. Don't go too heavy on the lubricant. Whether or not you have sticking at the throttle bodies I don't know. I'd go with the grip first.
Good luck.