Outboard Motor Anatomy: Part Three

Now that we have gone over the two cycle oil and gasoline specifications, as well as the benefits of the outboard motor, it is time to determine which model is right for you. The motor that you choose will be largely dependent on the hull of the craft that you plan to attach it to. Every boat built in the US has a “Guard Rating Plate”; this shows the maximum horsepower for the motor, but you should also be sure never to go below 75 percent of this number.

The other main spec to take into consideration is the shaft length. On outboard motors, this measurement is customized to fit 15, 20 or 25-inch transoms (the stern of the watercraft). When the shaft length is too long, there will be drag, while if the shaft is too short, it could lead to ventilation or potentially the overheating of the engine.