Prop size question

[bluemist]

Hi All,<br />I am currently running A 15 X 17 Aluminum prop. The next step down is 15 1/2 X 15. When the boat first goes in the water the max rpm is 4300/4400. After soaking, some growth, and my wife and son moving in, the rpm is shy of 4200.<br />At cruising speed i am very happy with the way the boat rides; although the holeshot is a little weak. Am I hurting the engine by using it this way? In my oppinion this boat was under powered from the start. <br />Thanks,<br />AL

 

[Haut Medoc]

Re: Prop size question

Depends on the size of the boat & how heavy....<br />I would try a 14 x 17 or 19.....<br />Has it been tuned up?<br />The rpm's should be higher, & you will do damage running it that way over time......<br />You would be better off posting this in the prop. forum, you will get more responces .....JK

 

[Purduebarry]

Re: Prop size question

Prop forum question no doubt, What is the RPM at WOT supposed to be? If it's not reaching the suggested RPM at WOT the engine will be lugging, which over time will cause serious engine / drive problems. How much growth? You are placing strain on the motor and drive = heat, wear, friction & failure. If your going to leave it in the water, paint the bottom with anit-fouling paint a few minutes at WOT and it's clean again.