New propeller

[Rupert]

Hi
I´m looking for a new prop for an old 70 hp 1986 yamaha o/b (13 splines) . 17 foot boat. At the moment I have a slightly tattered 11 1/4 x 15 G. I find it sluggish at low speeds especially in currents. I´m looking for better performance rather than speed and hopefully less fuel consumption. Does anyone have a good idea about choosing props? Thanks Rupert

[robert graham]

If your motor is running about 5500RPM's at wide open throttle, then your prop may be the correct pitch and diameter. If you're going from a beat-up aluminum to a new stainless steel prop then your performance could improve some. Regarding fuel efficiency, not much you can do about improving that, other than find your best cruise RPM's and stay there. Check:Yamaha Outboard Performance Bulletins for information on RPM's, GPH, GPM, etc. for your boat and motor. Most boats run most efficiently just above plane speed. Your motor is probably going to burn about 7 gallons per hour at wide open throttle, some less at say, 3500RPM's cruise speed. Good Luck!