Trolling Motor Questions

[Gill Fisher]

Hey Guys, my boat is a 15 1/2 foot "Scanoe," a flat bottom hard plastic canoe with a transom on the back for mounting an electric motor or it will handle a gasoline motor up to about 4 hp. I think it weighs about 80 lbs. I am using a Minn Kota Endura C2, with 40 lbs of thrust. When I get out on the water, I've just been letting the trolling motor go down in the water as far as it will go because that's pretty comfortable for controlling the motor. It puts the shaft at a comfortable position for me to operate. The shaft of the trolling motor, from the "Stop" just below the tiller is about 32 inches from the top of the part with the propeller on it. Is that called the "Head?" The transom of the boat is only about 12 or 14 inches tall, I'm guessing. So the propeller is, I'm guessing, about 18 to 20 inches deeper than the bottom of the boat. Now, if I were to raise the motor up so that it is only, say, 6 inches below the bottom of the transom, would that affect the speed of the boat? Does having the propeller deeper in the water have any affect on the speed of the boat?

A second question is; if I were to upgrade to a 55 lb thrust motor, would that make much difference in the speed of the boat? Or maybe I should ask; how MUCH would that affect the speed of the boat?

Thanks guys

GF

[Atimm693]

Hey Guys, my boat is a 15 1/2 foot "Scanoe," a flat bottom hard plastic canoe with a transom on the back for mounting an electric motor or it will handle a gasoline motor up to about 4 hp. I think it weighs about 80 lbs. I am using a Minn Kota Endura C2, with 40 lbs of thrust. When I get out on the water, I've just been letting the trolling motor go down in the water as far as it will go because that's pretty comfortable for controlling the motor. It puts the shaft at a comfortable position for me to operate. The shaft of the trolling motor, from the "Stop" just below the tiller is about 32 inches from the top of the part with the propeller on it. Is that called the "Head?" The transom of the boat is only about 12 or 14 inches tall, I'm guessing. So the propeller is, I'm guessing, about 18 to 20 inches deeper than the bottom of the boat. Now, if I were to raise the motor up so that it is only, say, 6 inches below the bottom of the transom, would that affect the speed of the boat? Does having the propeller deeper in the water have any affect on the speed of the boat?

A second question is; if I were to upgrade to a 55 lb thrust motor, would that make much difference in the speed of the boat? Or maybe I should ask; how MUCH would that affect the speed of the boat?

Thanks guys

GF

Moving the motor up or down will not likely have a big affect on speed. The only thing changing would be the amount of drag on the motor shaft. Less in the water, less drag.

Bigger trollers usually do not offer more speed, unless the original was undersized to begin with (which I don't believe is the case on your setup). You might gain a little, but probably not enough to bother with. Even the biggest baddest troller made would probably only do 4-5mph on your rig. They're made for thrust/torque, not speed. Need a gas motor for that.

[DockShootinJack]

For the cost of a trolling motor you can get a small outboard. I was looking at them last night. Most are not name brands that i recognize. Yet some are.

[skeetbum]

I was told years ago that for every 15lbs of thrust is 1 hp. Adding 1 hp wouldn’t give lots more speed but would probably give better handling on windy days. I moved a small Tm from the transom to the bow and got significant improvements in speed and handling. Doesn’t work for everyone but did very well to me. I hung a sash weight off of the back for a sort of tiller and that stopped the back end blowing around. Better speed for traveling distance would be better achieved with a small outboard.