Posts: 3508
Location: Elk River, Minnesota | Hiya,
I would bet when you are at highest trim and wide open throttle, the side spray is not very far behind the console?
With the motor flat on the transom and using an aluminum prop, I truly believe you can find more speed by changing to a steel prop and moving the motor up off the transom.
The Yamaha Pro Series in a 13-1/2 x 17 will be an excellent choice for your rig. It will do two things for you: First, it will actually act more like an 18 pitch prop because it is aggressively cupped, and being steel will flex quite a bit less than the stock white aluminum. Changing to this prop will be close to the same RPM level as you are running now with the motor on the transom. This is because switching to steel will drop your rpms by about 200, going to a larger diameter will drop the rpms another 200, but going to a 17 pitch will bring you back up 400 (200 for each inch in pitch).
Now...if you then raise the motor to the 3rd bolt hole up off the transom, you will be sitting right around 6000 rpm give or take.
With a guesstimated approximate 15% slip factor due to being higher off the transom, This would put your rig running right around 42 - 43 mph, which is right in the ballpark for that motor when you are loaded with just you and your gear.
Please keep in mind, these are just ballpark numbers as all boats will perform differently.
another prop to consider would be a michigan ballistic in a 13-5/8 x 17 as well..Very aggressive prop and would do well also.
I definitely think there is room to get a little more out of the boat... 40 is definitely possible...
Steve |
