Boat came with 15" prop stamped with "19-M". Whether or not this is truly a 19-inch pitch is open to interpretation. All I know for sure is what I can read. During the sea trials (flat water, no-wind day) she only came up to 5100 rpms on WOT, and it should be up around 5600. A few very knowledgeable people have said it's pitched too high, ya' gotta make some changes.
A boat guy in my area offered to let me try a Merc Stilletto 3-bladed prop with a 17-inch pitch. His blade is 14" diameter, not 15 like my prop. Hub is a little shorter than the Yamaha prop that came with the engine. It looks like it will need another washer between the nut and the prop to hold the nut out a little farther so that the cotter pin can engage the ears on the nut.
Questions: 1. Is it OK to put on the additional washer so that the nut won't go so far on the shaft; and, 2. Is the 14" diameter going to over-rev the engine? That is giving up a whole lot of surface area of blade biting the water.
There was some discussion a few weeks back about Merc props on Yamaha engines, and a few guys said they worked well. What was the name of the Merc prop - was it a Mirage or something like that? Thanks in advance. JF
A boat guy in my area offered to let me try a Merc Stilletto 3-bladed prop with a 17-inch pitch. His blade is 14" diameter, not 15 like my prop. Hub is a little shorter than the Yamaha prop that came with the engine. It looks like it will need another washer between the nut and the prop to hold the nut out a little farther so that the cotter pin can engage the ears on the nut.
Questions: 1. Is it OK to put on the additional washer so that the nut won't go so far on the shaft; and, 2. Is the 14" diameter going to over-rev the engine? That is giving up a whole lot of surface area of blade biting the water.
There was some discussion a few weeks back about Merc props on Yamaha engines, and a few guys said they worked well. What was the name of the Merc prop - was it a Mirage or something like that? Thanks in advance. JF