Courtney the Dancer
Join Date: Nov 2000
Location: San Juan Islands., WA, USA
Thanked 26 Times in 25 Posts
Rep Power: 16
Rxbot- you're correct, it is a feathering prop, or variable pitch. Each blade is completely independant of the others. They rotate on individual bearings and just flop around when you turn the shaft slowly. They are built so that the centrifugal force throws them out in the correct direction, forward or reverse, and the higher the RPM the finer the pitch until the boat speed increases the water flow over the blades so they increase the pitch. You really need to use a lot of throttle initially to get going or stop (but you can stop on a dime if you need to). In a rough sea where forward speed is constantly changing the blades change with the speed, continuously and automatically, without changing the engine RPM.
I don't think that this could be a prop issue if it is clean and the blades move freely (I would guess the diver would have checked this?), but I'm stumped about what might be causing it. Could there be fish line or something in the cutlass bearing creating a severe drag?
PS, I love the idea of the Autoprop and it works great, just not sure I'm going to put one on the new boat in light of the reports of the newer ones losing blades.
SV Laurie Anne
1988 Brewer 40 Pilothouse