Mariner 75 propellers
Just realised that my new boat with twin 75hp engines has two different props. One is 15 pitch and revs to 5,500 rpm and the other is 19 pitch and revs to only 4,000 rpm. To me 4,000 rpm seems a bit low, although I am certainly no expert! Obviously I need to replace one prop but I'm a little confused as to which size will be best for performance and fuel efficiency. Any help will be much appreciated!