Powerhead is single cyinder 2stroke, runs at 4000rpm, 3.1/l gear ratio, allegedly puts out 5.5hp at prop which is a 9inch 4blade. Motor is designed for heavy displacement hulls but I have it on a 12ft shallow draft aluinum planing hull. The only 2 ways I can see to increase hull speed is by changing gear ratio trying for more rpm at prop, or changing prop size. My question is would replacing the 9inch prop with an 11inch 5bladed "hydrofan" prop do anything for speed, pitch and prop rpm being equal? The only reason the boat won't go any faster now, is that the engine is maxed out on rpm at WOT and can't turn the prop any faster. Ny British Seagull freaks out there? Getting a different motor is not an option <g>
