Outboard Engine Alternators, Starters, Solenoids, Relays & Components

Outboard Engine Alternators, Starters, Solenoids, Relays & Components Resources and Information

PartsVu is pleased to offer a complete selection of essential components to fit your outboard engine’s exact specifications. Browse our extensive collection of alternators, starters, solenoids, relays and components to repair your outboard and keep your engine in peak performance for years to come. 

Looking for more marine products for your boat and outboard engine? Browse PartsVu’s products and accessories or aftermarket engine parts.

Outboard Engine Alternators, Starters, Solenoids, Relays, and Components FAQs

What is an outboard engine alternator? 

An alternator performs the important function of converting mechanical energy into electrical energy. As the stator and the rotor inside the alternator revolve, they produce an alternating current which supplies the battery with a consistent supply of electricity. This ensures your boat’s electronic components remain functional. 

What does an outboard starter do? 

A starter is a small electric motor inside your outboard engine that is responsible for actually cranking the motor. The starter consists of two main parts: the starter motor and the solenoid. The solenoid receives electrical energy from the battery and transfers the energy to the starter motor. In turn, the alternator’s starter wheel turn the outboard engine’s flywheel thereby “starting” the engine. 

What is a solenoid? 

A solenoid is fairly simply device that converts electrical energy into mechanical motion. The solenoid is composed of a wire coil, a plunger, and metal housing. When an electrical current is introduced, the wire coil creates a magnetic field. The housing, typically made of steel or iron, concentrates the magnetic field’s energy which, in turn, draws in the plunger. The solenoid is a crucial component of the outboard engine starter.

What is a relay? 

A relay is an automated electrical switch that switches an electrical current on and off. Additionally, a relay has the ability to switch multiple circuits of differing voltages at the same time. 

How can I improve my outboard motor performance?

A boat that’s over-propped can cause your outboard’s highest RPM to be lower than the wide-open-throttle RPM recommended by the manufacturer. This happens because the higher pitch causes more resistance to the water, keeping your propeller from revolving as freely as it can. The wide-open-throttle RPM is usually between 5,000 and 6,000 RPM, but refer to your owner’s manual to be sure.

Running your RPM below the recommended range will make the engine work harder. This increased workload causes your combustion temperature to rise and will stress your boat’s internal parts.

An under-propped boat can also be harmful. If the engine spins above the recommended RPM, it’ll wear down the parts, and your engine won’t last as long. You can adjust your engine’s wide-open-throttle RPM range by changing the propeller pitch. Increase the propeller pitch to lower the wide-open RPM or decrease the pitch to raise the wide-open RPM.

It’s also helpful to experiment with different propellers. Find propellers within your budget until you reach the performance you’re striving for.

One way to know if your boat is reaching the recommended RPM is doing a wide-open-throttle test using a tachometer, and your boat may be already equipped with one.

Boats handle best when they run parallel with their at-rest waterline — you’ll notice a more comfortable ride, increased speed, and more efficient gas mileage. The bow of your boat meets the water at a specific angle — and that angle has a direct correlation to how efficiently you operate your vessel.

For peak performance, set up your boat to use less positive trim. Be sure to point the nose of your outboard lower unit straight forward. That causes the thrust from the propellers to go straight aft. If you’re unfamiliar with the term aft, it’s a naval term that means “towards the stern (rear) of the ship.”

Outboards or lower units trimmed out have the noses point down, and the thrust is directed up. That means the thrust isn’t aft, reducing efficiency and increasing fuel consumption.

What are the common ways for an outboard to break down?

Over the years, we’ve heard some boat owners ask “Why are boats so unreliable?” The truth is, Yamaha outboards are incredibly reliable but require regular maintenance to stay reliable. This maintenance must occur at recommended service intervals.

Boater owners committed to regular maintenance will also often ask, “How many hours will a Yamaha outboard last?” While Yamaha makes a diverse line of outboard motors, most models will last 1,500 – 3,000 hours depending on how often it is maintained, stored, and used. Considering that the average boater racks up 50 hours of usage per season, owners can expect many years of use. This said, we commonly hear of Yamaha motors lasting well beyond 3,000 hours.

Performing routine maintenance at the recommended intervals prevents many problems and significantly contributes to engine life and performance.

One of the most common ways your Yamaha outboard motor will break down is a fuel system failure. Whether you’re experiencing an intermittent bog down, poor performance, or complete engine failure, your fuel system is a common culprit.

• Ethanol gasoline: Only use premium low-ethanol gasoline for your Yamaha outboard motor. The reason is that ethanol attracts water, causing fuel to dilute through “phase separation.” Additionally, ethanol gasoline can also gunk up fuel lines and fuel system components due to additives used. To help prevent these issues, regularly use a high-quality fuel stabilizer.
• Fuel lines: Check your fuel lines. If you discover any breaks or leaks, you should stop using the engine and make any necessary replacements. Also, take a look at any fuel hoses with an interior liner.
• Fuel filters: The fuel filter is designed to catch any debris and contaminants that have entered your fuel system. Regularly replace your fuel filters to keep fuel running freely.
• Fuel pump: A malfunctioning fuel pump can significantly reduce engine performance and, over time, severely damage other components. If your fuel pump is not working correctly, replace it and any hoses that may have been affected.

A common mistake newer boat owners make is that they dry start their Yamaha outboard motor. A continually flowing water supply cools an outboard engine—without a supply of water to cool it, an outboard motor will overheat. Additionally, the impeller, which is lubricated by the water, will begin to warp due to the heat and friction, further exacerbating the problem. 

To fix this problem, check your impeller. If the impeller is misshapen, you will need to replace it. Replacement is a simple fix for most amateur mechanics, but pay attention to any other issues that may have resulted from the dry start. Dry starting can cause serious engine issues and may require a rebuild by a licensed mechanic to restore it to working condition.

What causes a boat motor to lose power?

We always recommend carrying a spare in-line fuel filter. If your engine is losing power, first replace the in-line fuel filter. If you’re not carrying a spare, remove the filter, clean the filter element of debris, and drain any accumulated water.

A spark plug fouled by fuel, carbon, dirt, or oil may be unable to produce a spark strong enough to ignite the air/fuel mixture and start your engine.

Inspect each spark plug and also inspect the wires. If your plugs are fouled, use a rag to remove the build-up as best you can. If your spark plugs have been neglected, you might need to use a knife or similar object to remove larger pieces of build-up. However, be careful not to damage the spark plug or accidentally change your spark plug gap. 

If your spark plugs were significantly fouled, replaced them as soon as is possible.

Then, inspect your spark plug wires, checking for signs of aging such as cracking or brittleness. Next, inspect your terminals and connection points. If there are signs of corrosion, damage, or breakage, you will need to replace some of your terminals. However, make sure you use the proper crimper when installing terminals, or you might create a weak point in your electrical system—creating a new problem.

t’s possible to buy bad fuel, but it’s more likely that your fuel went bad sitting in your boat. If you left your tank nearly empty for long periods, condensation could build, introducing water to the gasoline. Your gas might also be bad if you did not properly treat it before storage. If this is the case, add a fuel stabilizer and make sure to run your engine long enough to get the treated gas into the engine as well.