Re: finding motor RPM'S?
You just asked the same question in two different ways. Every engine manufacturer specifies what RPM they want the motor to run at on any given boat with an average load at wide open throttle. That information is normally provided on a label or tag on the engine block itself or on the ID tag attached to the transom bracket. It will indicate the engines HP, serial number, model number and WOT RPM. That RPM will be 4500 - 5500 on many Johnson/Evinrude engines. Newer engines will typically be in 5500 - 6000 RPM range. Without a tachometer, you cannot tell how fast your engine is running at WOT. So there are two parts to this requirement. 1) what rpm the manufacturer specifies, and 2) what you actually observe for your boat. On a properly tuned engine, the setup and prop pitch and style will determine what RPM you actually observe. If its not in the proper range, you either have an incorrect prop or there are other issues with the boat or motor.
