The topping lift plays no part in the sail trim (see Don Gillette's sail trim forum). Sail trim for the main on the H216 iis controlled by the main halyard tension, the choice of the three mast stepping positions when you step the mast, the boom vang, the main sheet, the outhaul and, if your boat is equipped with a traveler, the traveler. The topping lift is used solely to keep the boom from clunking down in the cockpit or on your head when the main is not flying. It sould be slack once the main is raised.