[tahitisail]

My manual shows:
1. Continuous output rating 16hp at 3400rpm
2. maxium output rating 18hp at 3600rpm
3. maxium fuel efficiency at 2700rpm
4. maxium torque at 2900rpm
5. engine flywheel output and propeller power curves crossing at 3400rpm

In flat water with no wind what rpm does it take to get your boat to hull speed?
If you are running into a sea/headwind run it at a higher speed and if you want to conserve fuel run it at 2700rpm

I run mine at a speed that gets me pretty good speed and at a noise level that doesn''t sound like the damn thing is going to jump out of the boat.