Max-Prop

[Alan]

Roland (SV Rollin' Coaster (formerly Pisces)) tried to post this question, and for some reason failed. He asked me to post it for him:

I'm planning to have a Max-prop (17" diameter) installed next week on Rollin' Coaster (formerly Pisces). The engine is a Betamarine 38 with a gearbox reduction of 2:1. Has anyone else done that or bought a Jason with a max-prop already installed? I'm asking because I'm concerned about the available space in the rudder aperture. If you do have a 17" max-prop installed, did it require any modifications? What's been your experience with a max-prop? Appreciate any input. Roland

[Alan]

I had a Max-Prop installed on Norwegian Steam about seven years ago. Seaview Boatyard in Seattle did the installation. I am not sure what the diameter of my prop is, but I recall that Seaview had to enlarge the aperture a bit. The prop has been working very well. I definitely believe that I have more control in reverse and the speed under power has increased slightly The feathering certainly must improve the speed under sail, although that is difficult to verify.

[orego...@gmail.com]

You might find a 17" prop a very tight fit.  I installed a 16" three blade Max-prop on the Light Beyond and would not want to go larger.  Earlier this summer I built and installed a new rudder and took the opportunity to open up the prop cut-out a bit.  The Light Beyond has a 40 HP Volvo 2040 and I find the 16" prop will bog the engine down if pitched too steeply.  I can bury the stern at high RPM's.  This prop replaced a 15" two blade fixed prop (bad choice) and now putting along at 2600 RPM gives me about 6.2 knots ... easy on both engine and crew.  Can push to 7 knots if needed but rarely do.  The Max-prop does improve handling in reverse but I suspect you give up a bit to a fixed prop in forward.