I have a 21' pontoon with a 1994 60 hp mercury on it. Running a 11*13 prop at 5700rpm. If I go bigger pitch, will this help top end speed. Do I need a prop made for pontoons?
Merc brochure says that your engine develops rated hp at a max of 5500. You're close to that so I don't think you have much room to move.You should be running a 1.64:1 gearbox on that engine. The 60hp bigfoot version runs a 2.3:1 which would handle significantly more pitch for the same load on the powerhead which they said gives you added thrust. Catalog lists 19" pitch as the highest for yours and 26" as the highest for the 2.3. But usually thrust improvements are achieved by turning a larger diameter, shallower pitched, prop at a reduced rpm, but I can't tell if they increased the height of that 2.3 gearbox allowing for an increased diameter prop. From the available pitch options I'd say not. My Merc brochure also says that your engine runs 5000 to 5500 at WOT, so theoretically, you could go up to the next pitched prop -11x15- which should drop your rpm's to 5300 - 200rpm's per inch of pitch change- which is well within your engine's ratings. Might pick up a couple mph.Course poontoons aren't speed demons by design you know, so I wouldn't expect much.My2c,Mark
Right prop for pontoon?
Linear Mode
