How to Determine Outboard Motor Height

Boaters wanting to maximize handling and speed must pay close attention to the height of their outboard motor. The height of the outboard motor impacts performance of the boat as well as the safety of the boat. An outboard motor placed too low could easily become damaged by low lying obstructions under the water. The sizes of the outboard motor, the shaft length as well as the type of hull are factors when determining outboard motor height.

Step #1: Determine the Overall Height of the Outboard

Measure the distance between the top of the propeller and the bottom of the outboard motor to determine the shaft length. Ensure the outboard motor is secured to the stern of the boat. The bottom of the outboard motor and the top of the transom are aligned with one another.

Step #2: Measure the Exhaust Port

Measure the distance of the exhaust port from the water line. The exhaust port measures approximately one inch above the water line and allows the exhaust an unrestricted flow.

Step #3: Find the Maximum Speed

Determine the maximum speed of the boat. The speed of the boat determines the height of the outboard motor. For every 10 miles per hour the boat can achieve, the height of the outboard motor can be raised approximately one inch.

Step #4: Test the Outboard

Test the speed of the boat as it relates to the height of outboard motor. A raised outboard motor reduces the effort needed surrounding handling while increasing the speed. The lift of the boat is also decreased as well as increases the amount of time the boat reaches plane.

Step #5: Review Completed Work

Review the characteristics of the boat. In the event your boat has either an extended mounting bracket or transoms which have been extended, raise the height of the outboard motor by approximately one inch.