I have a 1976 Johnson 55 hp. I just bought this boat. The motor ran fine 2X. Then it would not idle good. Cleaned the carbs found some plastic from the needle screw lock thing broken inside. Put it back together Idled fine. Took it for a test run and it didn't have power like it used to. Took it to a mechanic and there is no compression on the #2 cylinder. NONE. Should I rebuild or Dump.