YS 91SR Back Plate - YSS9116 by YS Engine  [YSS9116]

Rear housing back plate for YS 91SR

This RC-scale replacement is the YS Engine YSS9116 back plate, made for YS 91SR model engines. It closes the rear of the engine case and is used during maintenance or rebuilds when the original is worn, damaged, or being replaced for easier service.

Installation is straightforward for hobbyists familiar with small nitro and fuel engines: remove the rear mounting screws, note gasket and seal positions, then refit the back plate while tightening fasteners evenly to maintain alignment. Follow standard workshop practice for small screws and seals to prevent leaks or misalignment.

For tuning and maintenance, the back plate helps keep crankcase alignment and sealing; replacing a worn plate can restore correct fit and reduce endplay that affects idle and power delivery. Treat this as a spare part and confirm fit with your YS 91SR engine before final installation.