Honda BF20D3SH Outboard - 15" Shaft Manual Start 6A Charging Tiller Silver. Overview. The BF20D3SH is a short-shaft 20 HP outboard for boaters who want a noticeable bump in usable power while still keeping the rig simple. At 20 HP, many small boats start feeling more "effortless"-you can carry more weight, hold plane more easily, and avoid running wide open all the time just to keep the boat moving the way you want.. This model is set up with a 15" shaft, making it a strong fit for short-transom