Re: two or four stroke
At full throttle there will be very little difference in fuel consumption. The four stroke will have better fuel economy at idle and at midrange throttle settings. How much difference is difficult to say. My suggestion would be to visit the Yamaha Marine web site. There you can select any boat, any engine size, two or four stroke, and view the performance tests for the various combinations. The test reports provide detailed fuel consumption data at various speeds.
