trying to understand what this means on my prop

I have a Quick Silver Laser II the numbers on the prop are 4816990 20P. I am not sure what all that means, I guess that the 20P is the pitch. That leads to my other question, what happens with more or less pitch?

Re: trying to understand what this means on my prop

20 ? will be pitch. In theory the boat will move forward 20? for each revolution of the prop. In reality all props have some slip, appx. 10% is reasonable. Lower pitch will be a lower gear ratio, better holeshot, less top speed. The most important question ? is your boat attaining recommended RPM at wide open throttle. Each engine will have a recommended range at WOT. For instance, my F150 recommends 5500 ? 6000 RPM at WOT. Pitch changes should only be made to achieve this RPM at WOT. My boat will spin a 21P lightly loaded at 55 MPH, but with a boat load of people I?ll switch to a 19P to maintain 6000 RPM at WOT, but top speed falls off to about 50 MPH. You will need to know your engine?s recommended operating range, your current prop pitch, and your current WOT RPM before consider changing pitch.

Re: trying to understand what this means on my prop

Thanks for the info it was helpful, I guess that I need to get my RPM gauge fixed in order to fine out what my WOT RPM's are.