"The pitch is matched using a
"The pitch is matched using a tachometer.
Although some would have you believe that you can look on charts or use "prop" software, those methods will only give you a starting point since they can not even begin to hope to take in all the variables.
When you match a prop you are looking to use one that will allow you to come within about 200 rpms of the max for your motor.
So, for example, if your max rpm is 5500 then you want to shoot for 5300 (give or take 50 rpms or so - not an exact science).
Additionally, the time of year that you "match" will have an effect on "how well it fits".
If you do the majority of your boating in the summer, then "propping" the boat in the spring or fall will leave the motor "under-performing" since you typically lose 10-15% of your horsepower during the height of the summers heat/humidity (requiring you to run somewhat less pitch).
If you boat all season (or as year round as possible in your area), you would ideally, at minimum, have two different props - one for summer and a different one for other seasons.
And while yet others may say that prop selection is "less critical" on lower horse motors so use what you want, I disagree on that point.
While the effects of poor prop selection are more "noticable" on larger horse motors it is just as important on the smaller ones - in fact, in order to keep my 9.9 horse "properly propped" I have three different pitched props that are interchanged as conditions warrant..."
