TC JOHNSON
New member
I have a 1991 15hp johnson 255cc outboard. According to the service manual there is also a 216cc 15 hp. The 255cc standard bore is 2.3745 inches and the 216cc standard bore is 2.1875 inches. I am doing a ring replacement on my 255cc and want to purchase the right rings. I am not boring the block to oversize .030--- iam only honing it and replacing the rings. Marine engine offers for sale only one set of standard rings to fit all johnson 15hp outboards built in 1991. These bore sizings are very different . How can the same rings fit both bores? I just want to get the right parts. Help!