Originally Posted by radmiral
I need to replace a bad set of props that came with my 1988 54 with 1292 's . They are 4 bladed and look like they have been redone. I only get 23kts WOT at 2300 . Does anyone have experience 3 versus 4 blades,and what size ?
While your engines may get to 2300 RPM do you have any idea of how close this is to max load?
If you are under propped you will achieve full RPM out of the engines but not get the same drive if the props are too small compared to if they were the correct size and pitch.
A stain gauge on the shaft is an accurate way to tell what is being produced by the engine, if not available the next best thing would be fuel flow metering showing what is being burnt.