When adjusting the spring pre-load on a motorcycle, a "turn" typically refers to a 360-degree rotation. In other words, it means rotating the adjustment collar or the preload adjuster fully around in a complete circle.
It's always recommended to consult the owner's manual or the manufacturer's instructions for your particular motorcycle to ensure you have the correct information and understand the specific adjustments required. These resources will provide precise instructions on how many turns or clicks are needed for proper spring pre-load adjustment on your specific motorcycle.