YS 91SR Precision Back Plate - YSS9116 for YS Engine  [YSS9116]

Back plate function and fit for YS 91SR

YS Engine YSS9116 is an aftermarket replacement back plate designed for YS 91SR engines and intended for regular servicing or rebuilds. It closes the engine rear and restores serviceability when the original plate is compromised.

Typical installation requires removing the rear mounting screws, observing seal positions, and reattaching the back plate with even torque on fasteners to preserve crankcase alignment. Use standard RC bench habits when handling tiny screws and seals to avoid leaks or misfitting.

From a tuning perspective, a straight, well-sealed back plate helps maintain crankcase integrity and reduces play that can influence idle stability and peak output. Confirm the part aligns with your YS 91SR engine before finishing the job.