best prop for small motor

[michaelmrc]

i have a 14ft aluminum boat with a 25 hp 2stroke mercury remote steering. it seems to get up on to plane ok now but would like to see a little higher rpm and little more top end speed what type of prop should i go with. it currently has a 3 blade aluminum not sure of the pitch or how to check it.

 

[steelespike]

Re: best prop for small motor

Before changing props you should optimize your setup.particularly the verticle height.Start with the antivent plate(just above the prop) about even with the bottom of the boat.Raise the motor 1/4 inch at a time with 1/4 inch sticks until just before ventilation becomes a problem.Be sure the clamp has a good grip and it pumps water.An inch could gain 2 mph.What year motor?Without prop size and Max rpm and speed can't tell what you need.Look on the barrel of the prop for a number -- X -- or a part number. Then give us your present max rpm and speed.And typical load and activity.You could get a Tiny Tach
simple to install can be used on any similar motor without regard to settings about $40.A GPS is best for speed.You may be able to borrow a shop tach.
Selecting a prop is like picking the best single gear in a transmission to do everything.It is very important for economy and the motors health to operate within its proper rpm range.