Outboard motors have been used on boats for years because they are versatile and come in a wide power range, so selecting one that fits your boat is relatively easy. For small row boats to large fishing and ski boats, there are outboard options that will work, and in configurations that can affect the performance and power necessary.
Short Or Long Shaft
Outboard motors come in several physical sizes, and getting the right one for the boat is essential. The shaft length of outboard motors refers to the length of the drive section between the engine at the top, and the gearbox and propeller at the bottom.
Boats with shallow drafts may require a long shaft drive section to ensure the propeller is underwater when the boat is underway. Alternatively, boats that sit deep in the water can use a short shaft design.
When the engine is running, the water movement around the propeller can cause cavitation or air pockets around it if the drive is not deep enough. When this happens, the propeller is less efficient, and the boat's performance will fall off.
Getting the correct length outboard motor can resolve that issue because it ensures that the drive and propeller are under the surface not just when the boat is idling but also when it is moving and planning across the surface of the water.
Some of the biggest performance gains for outboard motors come from the fuel and electrical systems. In years past, the outboard used a magneto and carburetor and were both prone to issues in some conditions. However, modern outboard motors use charging and electrical systems like the ones on cars, with an alternator and solid-state ignition that is reliable.
Many of the new engines also use fuel injection systems for better fuel management, and as a result, they can make significant horsepower in a compact package. The systems are standalone, so everything is housed inside the outboard case and cover, and the entire assembly can be removed and replaced if something goes wrong.
Taking your boat to a marine repair shop for service is still the best way to ensure the engine and drivetrain are in good shape, and in a pinch, you could remove the outboard and take it by itself to the shop for service or if you need an overhaul of the engine or electronics.
When looking for outboard motors for sale, you need to decide how large an engine and drive train you need. If you are repowering a fishing boat that is large and fast, you likely need an outboard with more power to push the boat across large water bodies. However, if you have a small row boat, johnboat, or dingy, you may only need a small outboard that has a few horsepower.Share