used for fishing and bring people and supplies to the camp, has a hard time getting on plane with a load, once I'm up it's fine. Need more power but don't want to lose to much speed. (not that fast now)
How will changing my prop size and pitch affect my speed,40 hp - 11 3/4 - 17 original 12 1/4 - 15 considering.?When you change your prop from a 17 pitch to a15 pitch you will get up on plane faster but you will loose 3-5 miles an hour top end.Your engine will also rev higher when you are full throttle.It is alright to use the smaller prop but you need to be sure that when you are driving at full throttle that you pull back the handle a little so you do not exceed the engines maximum rpm range.I hope this answers your question.How will changing my prop size and pitch affect my speed,40 hp - 11 3/4 - 17 original 12 1/4 - 15 considering.?Mrfixit is right. It seems like you can get on plane now, but your slower than you'd like. As you say you need more power. You didn't say the type or size boat, keeping in mind that different boats and motors act differently. Perhaps a different boat-motor would satisfy your requirements or two different boats, one for passengers and a different one for supplies. Frankly the prop change your thinking about will result in little change in power or speed. Good luck!How will changing my prop size and pitch affect my speed,40 hp - 11 3/4 - 17 original 12 1/4 - 15 considering.?your RPM's at WOT go up by at least 400, so take care not to overrev the motor.
your MPH at WOT will go down.
you want the antiventilation plate to be 1 to 2 inches above the keel -- if you have room to raise the motor on the transom, try that first.
