Problem has progressively worsened and is intermitent. At times the motor will operate flawlessly, starting with only a bump on the switch, build power rapidly and cleanly, rev to 5200-5400 rpm (everything you expect from a properly operating motor). On occasion it is difficult to start, will not rev beyond about 2000 rpm. It may stay like this for hours or only a few minutes then run fine. Fuel appears clean, filters fresh (h20 seperating), electrical connections appear free of corrosion. Fuel pump is fresh. Any ideas what to check next?
