Im new here and did a few quick searches but I couldnt find anything about the performance of the yamaha f115 4 stroke. I've got this engine on the back of a 19' polar bay/flats boat. I've had the motor checked out by the dealer twice. they supposedly put new injectors in and fuel filter but this still made no difference in the extreme lack of performance from this engine. I've had this boat/motor since 2003 since new. I do believe that the boat is water logged a bit because it sits in the water. SO my question is, has anyone one here done any sort of performance work to this engine to make more hp or tq such as... (this might sound rediculous but this is how underpowered it feels) supercharger or nitrous; haha but seriously? if this has already been brought up please just direct me accordingly. thanks guys