Rear Closure for 91SR3C Engines
This YS Engine YSS9216 back plate is an RC-scale spare designed specifically for the 91SR3C engine family. It serves as the rear closure for the engine case and is intended for routine maintenance, repair replacement, and setup work rather than performance enhancement on its own. The write-up below focuses on fit, installation considerations, and the part's role when servicing nitro RC engines.
Compatibility is limited to the 91SR3C designation as stated in the product name; do not assume fit with other YS Engine models unless confirmed by the manufacturer. The component is sold as a single replacement back plate, intended to restore proper sealing and alignment when the original plate is worn, damaged, or removed during overhaul.
Installation notes: check mating surfaces for burrs or old gasket material, clean the case face thoroughly before fitting the back plate, and use the correct torque sequence on the mounting hardware to avoid distorting the crankcase. If gaskets or O-rings are required by the engine design, reuse only parts specified for the 91SR3C or replace them with equivalent OEM items.
Tuning and workshop role: while the back plate itself does not alter engine timing or performance, correct installation affects crankshaft alignment and crankcase sealing which are important for predictable running and consistent tuning. Inspect the back plate for straightness during rebuilds and replace it when damage or warping is observed.
For hobbyists performing maintenance or replacing a damaged rear case closure, the YS Engine YSS9216 back plate provides a direct spare for the 91SR3C engine family and should be handled as a service part during engine teardown and reassembly.
