YS Engine YSS9216 91SR3C Service Back Plate Replacement  [YSS9216]

Service Back Plate for 91SR3C

This YS Engine YSS9216 back plate is supplied as a replacement part for the 91SR3C engine family and is intended for workshop maintenance and repairs. It closes the rear of the crankcase and is a service component rather than an add-on for increased power.

Fitment is specific to the 91SR3C marking shown in the product title; confirm compatibility with your engine before purchase. The item is sold as a single back plate to return the case to correct sealing and alignment after the original has been damaged or removed.

Workshop guidance: examine mating faces for remnants of old sealant, clean thoroughly, and avoid overtightening screws which can warp the crankcase. Use only the gaskets or O-rings called out for the 91SR3C when required.

Service impact: although the back plate does not change timing, correct seating preserves crankshaft alignment and crankcase pressure characteristics that influence consistent running and tuning work. Replace the plate if you detect warping or impact damage.

For anyone disassembling a 91SR3C for service, the YS Engine YSS9216 back plate is the intended spare to restore the rear closure during rebuilds.