Hello,
Bought my first Grady this year, a 2007 257 Advance. Like the boat very much, but like any new relationship still getting to know one another. She is setup pretty standard with a Yamaha F250 and a Salt Water Series II prop (15 1/2 x 17). The prop was in nice shape, but had some small (1/16 or 1/32") nicks so I had it reconditioned and they clearly removed just a little material to make it perfect.
So my dilemma. I obtained the Yamaha Performance bulletin for my boat, year, make, model, engine, prop ... pretty much identical. They indicated that with 300 lbs of people and 1/2 a tank of fuel that it performed optimally at 4000 RPM. At 4000 RPM they indicated 27.4 MPH and 9.1 GPH fuel consumption. I went out with my two children and light gear. So we had about 500 lbs of people and a full tank of fuel. At 4000 RPM I was moving 19 knots according to my GPS or 22 mph. To make 27 MPH I had to be turning 5000 RPM and consuming 14.5 GPH. UGH!
Motor did not seem to labor any any speed, runs nice, smooth and with little effort. Carrying an extra maybe 600 lbs between fuel and people, but this is 50% more fuel consumption and 20% slower. I attached the Performance Bulletin. I am not sure if the prop had too much material removed, etc. Has anyone had a similar experience or have any guidance. would really appreciate some assistance.
-Ron
Bought my first Grady this year, a 2007 257 Advance. Like the boat very much, but like any new relationship still getting to know one another. She is setup pretty standard with a Yamaha F250 and a Salt Water Series II prop (15 1/2 x 17). The prop was in nice shape, but had some small (1/16 or 1/32") nicks so I had it reconditioned and they clearly removed just a little material to make it perfect.
So my dilemma. I obtained the Yamaha Performance bulletin for my boat, year, make, model, engine, prop ... pretty much identical. They indicated that with 300 lbs of people and 1/2 a tank of fuel that it performed optimally at 4000 RPM. At 4000 RPM they indicated 27.4 MPH and 9.1 GPH fuel consumption. I went out with my two children and light gear. So we had about 500 lbs of people and a full tank of fuel. At 4000 RPM I was moving 19 knots according to my GPS or 22 mph. To make 27 MPH I had to be turning 5000 RPM and consuming 14.5 GPH. UGH!
Motor did not seem to labor any any speed, runs nice, smooth and with little effort. Carrying an extra maybe 600 lbs between fuel and people, but this is 50% more fuel consumption and 20% slower. I attached the Performance Bulletin. I am not sure if the prop had too much material removed, etc. Has anyone had a similar experience or have any guidance. would really appreciate some assistance.
-Ron
