Re: determining which prop to buy
This is what I came up with:
I ran the boat on pretty smooth water, but I had 6 people on board. 3 adults and 3 children. I don't know if that invalidates my figures out or not, but that is what I would have on the boat on a normal outing, when skiing. I was at the maximum on # of people and probably close to max on weight of those people.
I ran it with throttle all the way open and I trimmed the motor up as high as I felt comfortable doing, as my trim gauge, not sure of it's complete accuracy, was all the way up and RPM's seemed to be leveling out.
I had 4800 RPMs. Probably would go higher, if there were less people on board, but like I said, that's about what I would have weight wise on a normal outing where there would be skiing involved. When I go fishing, there's at most 3, but probably 2/3 of the weight I had above.
My current setup is a 14 1/2" DIA, 3 blade 24" Pitch SST RAKER prop stainless prop.
The engines manual states, that should run the boat at about 55-67 MPH. Prior to rebuilding the motor about two years ago, I know I had the boat at 57mph with a GPS, and I thought RPM's were about 5000rpm at that time, with me and 1 person on board. Felt like I had room to go. I didn't have the GPS's hooked up this past weekend, so not sure of mph, and I know that doesn't really matter.
The manual for the motor, states Full Throttle Operating Range to be between 4500rpm's and 5500rpm's.
I am looking for a prop that will pull a slalom skiier out of the water. With my current prop, the motor really bogs down, when I try to pull a skiier up. Without a skiier, my boat gets on plane fast and seems to have great hole shot. The boat is an 18' Ranger 373V with an Evenrude XP 150.
Thanks,