While gasoline-powered outboard motors are easier to operate and offer higher mileage, they come with pitfalls, such as environmental concerns. A solution would be to change out the muffler. Another solution would be to build an electric outboard motor by converting a gasoline-powered model. The process requires that you already have some knowledge of how motors work.
Shut off the gasoline-powered outboard. Unscrew the casing on the gasoline-powered outboard with a screwdriver. Unbolt the gas tank with a wrench and lift it off. Unbolt the motor and lift it off the engine. Unbolt the cylinders and pistons and remove them.
Set the electric motor in the gas motor's place. Match up the driveshaft with the motor. The two tips should be jarred firmly together perpendicularly and, upon turning the driveshaft, the motor should turn, and vice versa. Bolt the new motor in place.
Unscrew the wires from the sockets and unscrew the control panel. Pull the wires from the sockets and lift out the control panel. Replace the control panel with the 300-amp controller. Rewire as before. Wire the two main positive and negative wires to the motor. Pull the battery sockets outside the engine. Bolt the case back on.
Drill holes inside your boat at the back -- where the engine bracket is. Bolt the rack on. Drill one hole at the left of the rack as well as one end of the leather strap. Drill another similar one on the other side of the rack. Bolt one end of the strap to the left hole. Place the six batteries side by side and pull the strap over them tight. Drill a hole in the strap and bolt it in.
Bolt or clamp your outboard onto your engine bracket. Route the negative wire to the negative socket on the controller from the battery on the left. Route the positive wire from the left battery to the negative socket from the battery on the one right of it. Continue connecting all six batteries in series. Route the positive wire from the battery on the right to the positive socket from the controller.