Re: 1860 g3 50 hp 4 stroke what size prop should be used
Welcome aboard! I have an 03 1860sc w a 03 Yamaha 4 stroke F90 and I love this boat. My motor weighs 370 lbs. It obviously is different in performance than yours. I had issues w steering at high and low speeds and porposing and prop slip or blowing? out w the factory alum. 3 blade 13.25x17" pitch prop. I learned a great deal about props here at Iboats, Thanks everyone, and bought a Solas 4 blade alum. prop w 17" pitch last year. It made a HUGE difference in my boats performance. It almost jumps on plane at holeshot, steers/handles like a sportscar, and stays on plane at lower speeds now. I will not go back to a 3 blade on my boat/motor. When I bought the boat the engine was mounted all the way down on the transome and the cavitation plate was below the hull 1.5" +/-, I have moved it to the next mounting hole and it improved porposing a little, the top of the C-plate is still slightly below the hull when trimed to parallel w the keel. I may try to raise it higher soon as I believe these boats are extra sensitive to cavitation plate position. Solas props are cheap and you can get them here at Iboats marine store. I think a 15" would work well or 13" if you carry alot of weight. You need to check your RPMs at WOT to get the best pitch for your setup so the engine is in the correct range and not dogging or overreving. I assume G3 recommends the 15" pitch on the 50hp. I have found my boat is over RPMs w the 17" on the F90 about 500rpms at WOT.
