87121-ZY4-000 RR (BF175) Mark _x0013_2 Overview. The 87121-ZY4-000 RR (BF175) Mark is a genuine Honda marine engine decal intended to identify and designate the rear mark of the BF175 engine series. This decal supports the identification system of Honda marine engines and plays a specific role in maintaining clear engine model distinction. As a part of the external markings, it is essential for retaining the original OEM look and ensuring the marine engine's professional appearance. Designed acc