I have a 27ft pontoon boat with no trolling motor. I have an old 28-pound-thrust motor (foot-controlled, with broken steering cables) that I am looking to rig up. I know it's not big enough, but if I can get it rigged first, I will start slowly buying other used low-thrust motors and mount several down one side of the boat. The first issue I have is that I need to be able to adjust the output to partially match the thrust between motors at the front and back of the boat at times. I am planning on ripping the wiring off of the foot-pedal. Then I am going to try taking the the wires from the speed swith and use only the ones for the max speed, and put a voltage regulator between them. So instead of using different motor coils or however the current hardware works, I will drop the voltage to 6 volts to get half power instead. This should give me continuously variable thrust. Has anyone ever worked with these old motors and/or know whether a setup like this would work.

Also, I was told by a boat salesman that he had seen guys rig pontoon boats with a trolling motor at all four corners and build a controller to guide them. Has anyone seen or used one of these setups, know whether it was home-grown or commercially installed, and know how the setup worked.

My current plan is to rig two to four trolling motors down one side of the boat on swing arms. I will use a switch to change the polarity going to the back-end motors, and cabling to get all the motors to turn at the same time, with the front motor steered manually. So if all of the motors were turned sideways, I could use the continuously variable speed control to keep the motors in (or out) of sync to keep the boat parallel to the shore-line. If the switch is flipped, the boat would then have its front end going the opposite direction of the back end and would turn "on a dime" as it were. When chasing a school, the variable speed will be set with most of the thrust at the front and the polarity the same on all motors so that the back-end will just follow the front end along instead of driving the boat sideways. If all works as planned, the biggest problem is going to be figuring out a way to swing both or all four motors up out of the water at the same time so I can use the main motor. If they don't all come up at the same time, the steering cables are going to snap something off.

Sounds interesting though I have never seen a rig like that before. I can't help but wonder what it would be like to have to pull up 4 TM's. I've seen fisherman on many cases forget to pull up just one TM. Good luck with your project and post pictures of your final solution.

Why not just buy one solid thruster you mount on the big motor and then put another on the bow for guidance? You can get 100lbs+ mounted on the back end with far less rig-a-morrow than what you are talking about.

I have tried fishing with one at the bow (granted, it was this old 28lb). The problem is a matter of control. If there is any wind at all, a boat this size might as well be a sailboat. With a breeze blowing at all away from shore, I end up with trolling motor holding the bow pointed shoreward. Not too bad an issue, even with just one person. But if the breeze off the lake, the trolling motor has to hold the bow out into the wind, with the stern facing shoreward. In theory, you could balance the boat against the wind with the stern out, but its just not practical. Which means that if whoever is running the trolling motor wants to fish the shoreline, he is casting all the way across the boat to do it. And even with the bow pointed forward, only two people can really fish well. If I has multiples down the side, I could hold the boat with the side to the shore, and 4 or 5 people could all fish it with no problem. It could be done with just the bow and one on the motor, but it would mean that one person has to stay in or near the pilot's seat to control that motor, which wouldn't even be possible if I was fishing on my own (or with my wife and kids, which is the same thing). Besides the fact that I can get 4 used 25s for cheaper than a single 100+, especially with the premium of a motor-mount model. I know the four corners could work really well with servos and such, but I don't want to spend that much and haven't thought of a way to run steering cables across the boat and still be able to pull them up.

We had the same problem with a Toon we owned a many years ago.

So we had a TM installed in the front and one in the rear off a custom bracket welded onto the back of the starboard side.

If we were to do it again we would use a wireless TM for the stern and a foot/hand controlled for the bow that way a single person would have all the control.

My dad just put a Minn Kota tarova with auto pilot on his 26' triple toon. He doesn't have any problems with his. Or at least he hasn't complained about it....

I figured out how to lift them all. I'll run a length of pipe down the side above the motors, attach a crank at one end, and run a cable for each motor through a hole in the pipe. I'll crank it up like they do those awnings on the side of RV's and both or all 4 should come up together.

I've got some more thinking to do on the voltage regulator, though. I've built small ones before, but I forgot about the amperage requirement with the motors. I don't know how expensive power transistors big enough to handle 15 amps or whatever it is will cost.

Sounds like your gonna be busy-er than a cat covering up its own s--t.

Don't you mean a three legged cat?

Sound like a real rube goldburg to me. Buy one big trolling motor I know it will work. The thing you are building might sink your boat.
Johnny