What is the Max RPM range for a 1991 Evinrude 20 HP. Right now at full load and tank with a Aluminum 11x13 crisp prop and TNT and two people I get 4500 RMP at 20 to 21 MPH. With 1 person I get 5000 RPM and the same 20 mph ( I beleive spedo is not working right as I know I am going faster that with the second person). Is this right or should I be at 5500 RPM?
