help with prop

[david1420]

I have a 1998 <br /><br />proline 18'3" flats boat with a 1998 150 johnson i only turn 4900 rpms with a 14.5x18 raker prop i tried a 19" pitch turned 5000 rpms went to a 17' pitch turn 5000 rpms boat did about 38 mph with all three props does this sound ok and will it harm engine ?

 

[Dhadley]

Re: help with prop

Make sure you have your tach set on 6. It doesnt make sense that a 17 and a 19 turn the same RPM especially if they are from the same manufacturer and have not been rebuilt. Play with the jackplate height and let us know. The Raker should be close. <br /><br />Yes, overpropping (bad term) or lugging can definately hurt the motor.<br /><br />Good luck!