Restoring a 4148 Evinrude Fisherman. Finally got cylinders removed. Piston on one side had rings clasped on groove filled with carbon so tight continually working over a period of time with Blaster oil failed to budge. Need replacement piston ring for it. Part #100490. Also found on Sportfour models 9022-9025 and Lightwin model’s 4313-4313 and 4337-4341. Possibly other models. Would consider the challenge of a stuck powerhead to get one. Thank you.