I just recently purchased pontoon boat with a 2009 Evinrude E-TEC 90hp with low hours. It runs great and has lots of power but I noticed when I put it into gear (forward or reverse) I can hear a faint growl coming from the leg area. I think it is coming from the leg area because if I raise the leg out of the water in shallow areas the noise gets louder. As soon as I raise the rpm just slightly (just enough to notice a change of pitch in the engine)the noise goes away. I checked the leg oil and it full and looks nice and clear. I realy have to listen hard to hear the noise when it is in the water but it gets louder with the leg partialy out of the water. Is this normal, what could it be and could it be serious.