YS Engine YSS9116 Back Plate for 91SR  [YSS9116]

Back plate for YS 91SR engines

This is an RC-scale replacement back plate identified as YS Engine YSS9116, intended for use with YS 91SR model engines. The component serves as the rear closure for the engine housing and is used during routine maintenance or rebuilds where the original back plate is worn, damaged, or being upgraded for serviceability.

Installation is straightforward for hobbyists familiar with small nitro or fuel engine service: remove mounting screws from the rear of the engine, note gasket or seal locations, and refit the back plate ensuring even torque on retaining fasteners to preserve alignment. Use common RC workshop practices when handling small screws and seals to avoid leaks or misalignment.

In tuning and service contexts, the back plate plays a supporting role by maintaining crankcase alignment and sealing; replacing a compromised back plate can restore mechanical fit and reduce play that affects idle stability and peak performance. Treat this as an RC spare part, and verify fit against your YS 91SR engine assembly before final installation.