earney
20.04.2021 10:04:08
I f using an auxiliary mounting bracket: With the bracket in the down position, measure from the top of the bracket�s mounting surface down to the bottom of the hull or keel (lowest point where engine will be mounted).
See full version: How to determine shaft length on outboard motor
I f using an auxiliary mounting bracket: With the bracket in the down position, measure from the top of the bracket�s mounting surface down to the bottom of the hull or keel (lowest point where engine will be mounted).
Tip: If you are using a auxiliary motor on a shallow Vee hull where the main power is a jet in a river where you may be fishing in shallower and changing water, then the shortest shaft (even with the anti-cavitation plate slightly above the hull bottom) may save the prop from a bad case of rock rash. See diagram below.
Outboard Motor Shaft Length & HP to Boat Calculating
If measuring an existing outboard: Measure from the inside top of mounting bracket down to anti-cavitation plate above propeller (this is the largest plate/fin directly above the propeller). See diagram below.
Outboard Motor Shaft Length: How do I measure?
If mounting directly to a boat transom: Measure from the top of the transom down to the bottom of the hull or keel
(lowest point). Measure the area of the transom directly where the engine will be mounted. This measurement is primarily designed for single motor propulsion. A deep Vee hull will result in a different measurement than a flatter bottom hull. As you will see in the chart below there is nothing set in stone.
Picking the right shaft length is mostly a factor of the transom height or the back of the boat. But in many cases, it’s a little more complicated than that alone. Boat hulls are designed in three basic types that range from slow displacement and semi-displacement hulls to the fastest planing hulls. more
One of the great things about an outboard motor is how versatile it is. An outboard motor can drive just about any sort of boat with proper mounting. Beyond motorboats designed for large outboards, you will see outboards hanging on the sterns of everything from small canoes to large cruising sailboats. Many single-engine boats mount a smaller auxiliary motor for emergency use.
Many boat transoms are modified to use a different length of outboard by using a bracket. Offshore vessels are often equipped with a large mounting bracket so that the transom can be left at full height. This provides seaworthiness and offers maximum protection from large seas. These allow the mounting of a standard length outboard behind the transom. more
If you’d like to see this in video format, skip to 0:44 in the below YouTube Video: [links]
Amazon has plate extensions to allow adjustments without buying a new motor: T-H Marine Jack Plate Extension
The faster your boat, the more critical it is to get the sizing just right. If your boat planes, pay extra attention to getting the shaft length as close to perfect as possible. An inch or two probably won’t make a big difference, but any more than that will lead to trouble. Problems with getting the ventilation plate too low include slower hole-shot and lower top-end speeds. Bass boats, ski boats, or center cockpit vessels will want to double-check their measurements to get it just right. The performance of these boats depends on quite a lot of factors, but getting the outboard length just right is an essential first step. more
Read my other articles on outboard motors.
Outboard motors designed with electric start are started by activating an electronic switch. This feature is more convenient than a manual design that uses a cord you must pull to start the motor. here
An outboard motor is an engine designed for small watercraft that mounts on the back, or stern, of a boat. This part of a boat also is referred to as the transom. An ELPT outboard is an acronym meaning the motor has electric start, long shaft and power trim features.
The shaft is the portion of the outboard motor that connects the top of the engine to the propeller. For a long shaft design, the distance between the top of the motor and the propeller generally is 20 inches. Long shaft outboard motors are favorable for boat transoms that are 18 to 21 inches high.
Power trim allows you to adjust the angle of the outboard motor electronically as it moves through the water. Manipulating the trim is useful in keeping the boat level depending on factors, such as speed, boat design and the amount of weight on board the watercraft.