Trying to help out a guy here at work, , , the boat is a 06 Lund 18 foot Lund Fisherman, sorry I don't know the weight. The outboard is a 140 four stroke Suzuki, he's running a 13 1/4 X 23 prop.
His complaint is that with 3-4 people in the boat he's lucky to get up on plain, if he does it takes forever and people have to move to the front of the boat. With one person in the boat it doesn't really jump up on plain but obviously it gets there faster. I can't imagine this would be normal operation for this rig.
He says he's running 43 mph (GPS) though I don't know what rpm he's turning or how many people in the boat.
My innitial thinking is that he's over propped, but to further establish this I need to know what WOT RPM should be.
Soo, would somebody know what WOT RPM should be for this motor? Please ad any thoughts you may have on prop size etc.