Howdy,<br />I have a 1998 30hp 2-stroke (3-cyl) engine on my 13' whaler and would like it to have some more top end speed. It has the stock 9 7/8 X 13-f prop.<br /><br />Would a prop change help / work? If so what size would you suggest? Are 4-blade props more efficient?<br /><br />Another idea: I have heard some engines are fairly easy to increase HP. Would it be possible to increase the engine's displacement / hp with internal engine rework (swap block - pistons - head)? <br /><br />Thanks,<br />John
..<br /><br />you really need a tach to know if there is more performance to be had from a higher pitch prop. Otherwise you are just guessing and you could end up overpropping your engine which will cause it to actually go slower than full potential. About the only advice I can give without a tach is if it really jumps up on plane that suggests you could handle a higher prop pitch. Get a tach or maybe try the whaler chat board and see what other 13' set ups there are.<br /><br />By the way 4 blade props don't go faster, at best they go no slower than 3 blades. They improve holeshot and control. inch for inch Stainless props go faster than aluminum.