Re: Pitch on 150 Evinrude?
Hard to say without all the info but your local marine dealer should be able to help. The one I use has even let me use a prop for a weekend to see if I liked it. That said, there are some minimal requirements for your boat. You need to get an owners manual or do some research and find out what the max RPM is for the that engine. Whatever prop you go with needs to have your motor turning at or just below max RPM when at full throttle. Too little prop and you could over rev the engine or run it hot even at mid RPMs. Too much prop and it will be under to much load all day long which has a hole new set of problems. The diameter and pitch will effect this issue. If you have a heavy boat, a larger diameter 4 blade prop with less pitch will keep you on plane but it will cost you a few mph and some fuel. If you have a boat that is a little lighter, you can get away with 3 blades and a little less diameter with a little more pitch. I would think something around 16-17 in diameter or slightly smaller with about 19 - 21 pitch would get you close. 3 vs 4 blades depends on use of boat and weight. 4 blades give you more "bite" on the water but are slightly slower on the top end and are a little less fuel efficient. Fuel use is usually not enough of a difference that you will notice unless you are making really long runs and needing lots of fuel, so I don't usually allow this to sway my decision when it comes to prop selection. I fish where I need to get up on plane fast, so a 4 blade prop is a must on my bay boat. But, on my offshore boat, 3 blades do the trick and save me some $$$$.
