I didn't realize that I was going to have to know this before taking my PYI Max Prop off for re-conditioning! I'm pretty sure it's left hand rotation. Boat is a Catalina 320 with Yanmar 3gm30F and Kanzaki KM2P transmission with gear ration 2.21 as seen on the stamp. I had the yard remove the prop and I didn't realize that they would remove the blades in the process of getting the prop off the shaft. When they gave me the prop, the blades were really in an odd configuration, which really freaked me out until I realized that they simply were a little careless in putting the assembly back together! As seen in the photo, one of the leading edges is reversed! Look which way blade 3 is pointed! The fact that it is marked on the opposite side is a clue.
The problem is, I don't really know which way the leading edges were oriented before this was taken apart. I guess I just never focused on this issue. Since 2 of the tree blades come to a stop with leading edge forward when rotated ccw (viewing from the trailing edge) I assume it is left hand. But I'd like to know if there is another way to confirm it. Yanmar specification sheet for 3GM30 says crankshaft rotation is CCW when viewed from the stern. I've heard some transmissions can drive the prop shaft in the opposite direction, but that doesn't appear to be the case.
The problem is, I don't really know which way the leading edges were oriented before this was taken apart. I guess I just never focused on this issue. Since 2 of the tree blades come to a stop with leading edge forward when rotated ccw (viewing from the trailing edge) I assume it is left hand. But I'd like to know if there is another way to confirm it. Yanmar specification sheet for 3GM30 says crankshaft rotation is CCW when viewed from the stern. I've heard some transmissions can drive the prop shaft in the opposite direction, but that doesn't appear to be the case.