Posts: 1682
Location: Mt. Zion, IL | i know i am talking apples to oranges, but on my evinrude 50 etec on a 17' aluminum deep v tiller, 4 blade 19 pitch (much different gear ratio from Evinrude to Merc, but recently switched to a 4 blade from a 3 blade for the same reasons you mention. I set the height 1st correctly by running the boat. This is really the only way to dial in the correct height. The anti-ventilation plate should ride just on top of the water when running. You can find several pictures online of the merc performance boats with 5 or 6 400R motors and all the plates are just above the water level, even for ocean setups.
basically i switched from a 3 blade ss (evinrude viper) to a 4 blade ss (evinrude rogue) due to so much stern weight. Evinrude's catalog calls out this specific prop for high stern weight boats and advertises faster speeds and time to plane. While i don't feel it offers any advantage in time to plane, it is significantly faster. I could only trim up about two touches of the button by myself vs about 10-12 degrees with dad in the front of the boat with the 3 blade mounted. The 4 blade prop lifts the stern and i can actually trim the boat up more with the 4 blade, even with 2 more guys in the boat.
If you are just even with the bottom of the boat, i would look at going up at least an inch, possibly 2 more if possible. You may have to mount the motor to the jack plate by using a lower set of holes.
3 blade by myself - 30.2 mph 5640 rpm
3 blade with 2 people - 33.4 mph 5850 rpm
4 blade by myself - 38.4 mph 5730 rpm
4 blade with 2 people - 35.7 mph 5620 rpm |
