I bought an old Monark Jon boat with a 9.5 Evinrude. The seller told me the out board was a 1977 model. But in rebuilding the carburator, I having some doubts. The Model number is 9523C with a serial # E01901. While the new gaskets and float asembly match the old ones, the description of the "slow speed needle valve" (Clymer Shop Manual) doesn't. Any help would be most appreciated.