I have a 1990 Sea Pro 180 CC that has a step in the transom at the bottom. The step is approx 32 inches wide and 6 inches tall at the keel. It tapers to about 3 inches tall where the transom does not have a step on the outside edges. The step also goes in about 7 1/2 inches deep in toward the bow.
I currently have a budget project going and I have a 1975 115 Johnson set up in the lowest hole, which puts the cavitation plate about one inch above the keel. With the motor trimmed all the way in it is still about 9 1/2 inches away from the step of the transom and about 5 1/4 inches below the top of the step. Sorry I don't have any pictures.
I just got the motor running where I am confident that I am getting the power I can out of it and I am turning 4500 rpm with a 17 pitch prop. A couple of prop calculators have recommended a 17 pitch for speed. I also feel that this motor should spin it past 4500 rpm if it is set up right.
My next course of action will be to raise the motor. I plan to go up at least two holes, maybe all three. How much of an rpm increase can I reasonable expect by raising the motor? I have heard on here before that you can raise motors a little higher than normal on boats with a steped transom. Is the true of just a myth that someone put out there. I did add a tell - tail to this motor so I will be able to verify that it is pumping water and that the pick up is still in the water. Looking at the motor in the water it does seem to be lower than it should be when running. Throws up more spray then other boats.
The boat has also always had a prop torque problem. Will raising the motor help with this? I currently use smart tabs to help off set this, but they also kick up a lot of spray in the water. Hopefully raising the motor will also help with this. Does anyone have any other suggestions or warnings before I began to change the set up around? Now that the motor is running good I would like to get a little fishing in. Thanks in advance for any help.
I currently have a budget project going and I have a 1975 115 Johnson set up in the lowest hole, which puts the cavitation plate about one inch above the keel. With the motor trimmed all the way in it is still about 9 1/2 inches away from the step of the transom and about 5 1/4 inches below the top of the step. Sorry I don't have any pictures.
I just got the motor running where I am confident that I am getting the power I can out of it and I am turning 4500 rpm with a 17 pitch prop. A couple of prop calculators have recommended a 17 pitch for speed. I also feel that this motor should spin it past 4500 rpm if it is set up right.
My next course of action will be to raise the motor. I plan to go up at least two holes, maybe all three. How much of an rpm increase can I reasonable expect by raising the motor? I have heard on here before that you can raise motors a little higher than normal on boats with a steped transom. Is the true of just a myth that someone put out there. I did add a tell - tail to this motor so I will be able to verify that it is pumping water and that the pick up is still in the water. Looking at the motor in the water it does seem to be lower than it should be when running. Throws up more spray then other boats.
The boat has also always had a prop torque problem. Will raising the motor help with this? I currently use smart tabs to help off set this, but they also kick up a lot of spray in the water. Hopefully raising the motor will also help with this. Does anyone have any other suggestions or warnings before I began to change the set up around? Now that the motor is running good I would like to get a little fishing in. Thanks in advance for any help.