"Diameter and Pitch are usuall
"Diameter and Pitch are usually stamped between the blades or may be "encoded" in the model number of the prop depending on mfg (which is sometimes located around the inner hub face).
Is there a "standard" prop. The answer is NO. The prop must be fitted according to the boat it's on and if the dealer does their job properly, you will have to answer a number of questions as to how you use the boat and what you would consider a standard load.
In fact, most motors now of about 40 horsepower or more do NOT come with a prop for that very reason.
You are going to use a drastically different pitch if that motor is on a boat with a max rating of say 75 horses compared to a boat with a max rating of 125. Also, "Bob" may run a 13 pitch because he always goes out with 2 buddies - you could run a 15 pitch or greater because you go out by yourself with less gear/fuel etc even if your boats are identical otherwise.
The pitch is determined by loading your boat "normally" and then running it wide open and recording the rpms. If they fall in the optimal range (about 250 rpms below max as determined by mfg) then you are propped correctly - lower or higher rpms would indicate a pitch change is required.
There are prop calculators out there which can give you a starting point, but it is really a tach on the actual rig which is required to determine what prop you should be using..."
