Q2: what new propeller should I purchase for a 1986 MONTAUK 17 with an E-TEC 90 to improve its performance?
The performance data below is collected multiple runs at each data point from testing the following.
DATE: July 12, 2025
BOAT: 1986 MONTAUK 17 with 18-gallons fuel and 215-lbs crew weight
ENGINE: 2014 E-TEC 90 mounted two-holes-up
PROPELLER: BRG [later clarified to be three-bladed BRP] aluminum 13.25-inch x 17-pitch
ENGINE BOAT
RPM MPH
3000 19
4000 26
4500 29
5000 33
5500 34
6000 37
REMARKS
I recorded the data as best one person can do. On-line discussions anticipated the top boat speed would be greater than 40-MPH. The top speed in the testing was only 37-MPH
I am not a speed demon, but, if a different propeller will be more efficient, then I want [the added speed a different propeller will provide due to its greater efficiency].
[Deleted remarks in the form of a narrative that attempted to describe what a graph of the above data looked like. Just include the graph as an inline graphic so readers can see the relationship. Describing something that can easily be a graphic illustration in a narrative is not a particularly useful way to demonstrate the data shown in the graph.]
The top boat speed was 37-MPH.
The boat reached planing speed at an engine speed of 3,000-RPM.
The feel of the boat at engine speed 4,000-RPM and 26-MPH boat speed is wonderful.
Acceleration [of either the engine or the boat speed] from idle is huge.
I am not a propeller expert.
To me it seems the engine is going past the point of maximum horsepower, which I believe occurs at 5,200-RPM.
--Glen