Requirements for a Successful Re-power Project with Bill Grannis


When the time comes to upgrade your outboard for a later model, it’s not a matter of just bolting on the new engine and heading out to the water. There are a number of items that should be inspected, repaired, or replaced in addition to installing a new engine. Some of these components, if not up to spec, may affect the running characteristics, the warranty, and even your safety.



A boat consists of various systems that have to be in peak condition for not only reliability, but for the proper operation of your new powerplant. Electrical components, controls, oil tanks, fuel system, and steering, etc. could be worn, corroded, or not up to the task. Each item should be inspected by a trained professional to determine its condition and suitability.


Occasionally sales incentives may include new or reduced priced rigging items as well as extended warranty coverage. Ask your dealer about any current promotions that are in effect which can save you money.


Most outboard manufacturers do not allow motors to be sold “in-the-box” any more. Dealers are required to install and test run the engine before a signed report  is sent for warranty registration. Some folks may rig the motor themselves and have the dealer inspect the installation, prep the engine for starting, and test run the new outboard. If you elect to do the work yourself, please download and study the latest Evinrude E-TEC Pre-Delivery and Installation Guide from the SUPPORT section of



The first thing evaluated must be the boat, especially the transom condition. Not only is the proper transom height important, but any softness from rotted wood should be corrected before engine installation. Will the new motor exceed the maximum rated horsepower of the hull? If so, that is illegal in many areas and could possibly expose both you and the dealer to liability issues.



Steering systems are often overlooked. If hydraulic, are there any leaks or corrosion in the cylinder or the helm? On push-pull cable designs is it stiff or “jerky” when turned from lock to lock? Is the system adequate for the new power? Steering condition is an important safety concern and is subject to regulations.



The electrical wiring requires inspection plus the battery has to have the correct capacity for the new outboard. No wing-nuts are allowed on the batteries as stated in the owners manuals and installation guides.Batterycables have to be fastened with stainless steel lockwashers and hex nuts.  Gauges and warning horns must be the proper ones for your new engine but better yet, replace them with the latest digital display styles such as I-Command or the new ICON series. Most of the time it is recommended to replace the old electrical items as there may be hidden damage and/or corrosion inside the wires or connectors.



The control box is another item subject to wear and may need replacement. The cables should at least be replaced with new high-efficiency styles for smoother operation. You may want to upgrade to the “fly-by-wire” electronic shift and throttle ICON controls that are for available for certain models. These are great for multi-engine rigs and have push-buttons for one-touch engine synchronization and for incremental rpm changes. The latter is especially handy for fine tuning an exact trolling speed or compensating for changing sea conditions.



Last but not least is the vessel’s fuel system. If an adequate amount of clean gasoline is not delivered to the engine, it may run poorly, lack power, and the motor could be severely damaged. There are Federal regulations concerning fuel-systems that must be adhered to as well as the marine industry’s accepted practices and procedures for recreational boats.


Coast Guard approved fuel lines with a 3/8″ inside diameter are suggested as ethanol laced gasoline may deteriorate older hoses; plus, the new ones meet the latest EPA regulations. Look for A1-15 or B1-15 imprinted on the new-style hoses. A boat mounted fuel-water separator in addition to the on-engine filter assures contamination-free fuel for your outboard.



After the motor has been inspected, prepped, and started by a factory-trained technician the fuel system must be tested with a vacuum gauge and clear hose or the factory fuel-test kit. This helps determine if there are any air bubbles affecting the engine’s operation.



The final step in a re-powering to determine the correct propeller for new outboard as the old one may not be the right size, style, or allow the recommended rpm. This has to be done on the water with a normal load of fuel, gear, and passengers requiring several props in different sizes to determine which is best for your application. Evinrude publishes a technical booklet on how to choose a prop as well as several videos illustrating the process.




After the test run, your dealer should discuss the features, operation, maintenance, and warranty concerning your new purchase. Both you and the dealer have to sign the pre-delivery form as required by the factory. You can now enjoy your rig with friends and family knowing that your new Evinrude is set-up correctly and that all boat systems are safe and operational. Boat safe!