I have an 11'2" Mercury inflatable with a 2003 9.8hp Nissan four stroke. The boat goes plenty fast with 2 people. Unfortunately with 4 it won't plane. I have lifters installed which are like smart tabs and they help, just not enough. (the boat can maintain a plane at 1/3 throttle w/ 2 people) The boat almost planes w/ 4, so I was hoping a propeller change would make the difference. <br /> First off I am unsure which propeller I have. The guide online http://www.nissanmarine.com/tech_talk/prop_chart2.html? says I have an 8.5 X 8.5 My owners manual says it comes with a 8.9" X 10". Measuring it, it seems closer to the 8.9"<br /> Whatever the case, I need to know what propeller size I should step down to, in order to get the boat planing with a heavy load. I guess I need a smaller pitch, right? What size would you guys recommend? <br /><br /> thanks - Matt