My Mercury ME 5M 2-stroke starts easily, but the "start indicator" throttle position runs it at what sounds like 4000 rpm to my ears. If I throttle down, it begins to die. I don't know the engine's history much, but it was running prior to me getting it ... it has set for about a year.
- I began with a new spark plug, NGK BPR7HS-10 as the book recommends.
- First start was crazy high rpm, sort of got me very concerned.
- Redid lots of stuff in the fuel system: cleaned tank out, new pickup tube.
- The vent is open on the tank.
- Cleaned the carb twice. Both jets removed and cleaned, cleaned all ports.
- I tried draining the fuel bow while running.
- I tried a test of running with fuel tank disconnected. It revved higher after a minute, so I discontinued my test.