Either be sure it has a proper tune, doesn't have a fuel leak, or don't bother running it at all. All three, especially in combination, will save fuel.
I'll chime in that sharp blades might reduce the amount of mowing time, produce a better product, and might save a little fuel. It will take about "X" amount of fuel to produce 14 hp, but I wouldn't reduce RPM in an effort to save on fuel.:smile:
Why don't you define for us "a lot of fuel"? Does your mower have a 3 gallon tank and run 4 hours on that much? You make a very confusing query. For an engine of that hp I would say it should burn about 2/3 gallon per hour while at full engine speed, like for mowing.
