Re: Gas mileage?
For best gas mileage---leave it in the garage! LOL. Seriously, as stated above, you will acheive best mileage at "cruise" settings. At full throttle you can expect lousy mileage no matter what you do. My 125 on this boat goes through 15 gallons in about an hour at full throttle and 5900 RPM. 'Course, I don't have it set-up for best mileage, only high speed.
You can also be certain that the prop is good, with no large nicks or bends and sharp leading edges. AND, because stainless props generally run a couple of hundred RPM faster, a stainless prop will deliver slightly better fuel mileage at cruise settings. Be certain the trim setting is tilted for best efficiency at cruise speeds. Ruthlessly eliminate ANY excess weight and un-needed equipment. It costs you money to drag them around. Get a small girlfriend (or significant other) LOL.
You can also try raising the engine on the transom so the cavitation plate is about an inch above the hull bottom. This give less lower unit in the water and less drag. You need to experiment and be careful here, as too much height will cause the engine to ventilate.
Remember: Drag is your enemy. It causes you to use mare fuel to go a given distance. Be certain the hull is straight with no "hooks" or "rocker." Be sure it is clean and smooth. Remember, The less drag the whole boat has, the faster it will go at full throttle and the fuel efficience will be better at all speeds less than full throttle.
