outboard motor service

Annual Outboard Motor Service: Yes or No?


A new outboard boat engine can easily cost you the price of a car. If you take the time to have your car regularly serviced, shouldn’t you do the same for your boat engine?


Boat engines are used in a harsh environment that is going to clog and corrode your engine. Having annual outboard motor service done will ensure proper function so you don’t get stranded while out on the water.



When Should You Get Boat Motor Service


There is a debate about how often you should get servicing done, either 100 hours or one year. You will hear people refer to these interchangeably.


They are not the same thing and should not be treated as such. If you use your boat a lot or year-round in a tropical climate, you could easily put 100 hours on your boat in a season.



New Motor


If you invested in a new motor, don’t you want it to last? Having it serviced annually ensures that any potential problems are found and addressed right away.



Used Motor


Buying a used motor is an affordable alternative, but it may also come with a host of potential problems. If you bought a used model, have it serviced annually to ensure that it will last.



You Notice Things Are “Off”


If you’re noticing the signs that you need a boat repair service, it’s too late for your annual checkup.

When you neglect your engine, problems that would be found in the annual service go untreated.



Types of Engines


Before you go to do the annual maintenance on your boat engine, you need to know what kind of engine you have. Different types of engines require different maintenance.


To make it even more confusing, boat manufacturers construct their engines differently. This means you need to know the make, model, and year of your engine.



Two Stroke vs. Four Stroke


When choosing between a two stroke vs four stroke outboard you need to know the difference. A two-stroke engine means that the piston only makes two strokes in the time the crankshaft makes one revolution. One stroke is counted by the piston moving in one direction.


This means that the piston will go down and up, two strokes, in the time that crankshaft makes one revolution.


A four-stroke engine works the same way, except the piston makes four strokes instead of two. This means that the piston will go down, up, down, and up again in the time the crankshaft makes one revolution.



Carburetor vs. Fuel Injection


Carbureted engines have jets that push the fuel into the combustion chamber. The amount of air to fuel ratio can only be estimated.


These models tend to last longer than the fuel injected version. They’re also much easier to perform maintenance on since there are no electrical components.


Fuel injection motors tend to perform better as there is an electrical system regulating the fuel to air ratio being injected into the cylinders. There are two different versions of fuel injection, port and direct.



High Pressure v. Low Pressure


When the fuel is injected straight into the combustion chamber via direct injection, it requires a high amount of pressure. Only low pressure is needed to inject the fuel into the intake tract or cylinder port.


Direct injection tends to have a higher output of power. It also provides better fuel efficiency and lower emissions.



Your Annual Service Checklist


When taking your boat’s outboard engine to be serviced, there is a list of items your mechanic is going to check. This will help ensure that every part of your motor is serviced.



Perform a Compression Test


The compression test measures the amount of pressure the pistons create when moving along the shaft. The right amount of pressure is required so that it can be effectively lit by the spark.


If the piston doesn’t have a good seal with the shaft, then there are leaks and the pressure isn’t high enough. If the seal isn’t good, then the heat created by the piston cannot be transferred to the shaft.


When the heat is not transferred, the piston will stick to the shaft. A sticking piston will cause damage to your engine.


The basic concept of checking the pressure is a simple one – just use a gauge. The problem comes in with the required procedure in how to check the pressure and reading the results.


Manufacturers build their motors in their own way, meaning each motor will have a different process to get to the engine to attach the gauge. They also don’t distribute compression pressure information for you to compare your engine to.



Replace the Spark Plug(s)


Spark plugs are vital to the smooth running of your engine. They create the required element of the spark in the combustion of the fuel and air combination.


Many people will tell you to change your spark plug every year. This is good advice if you store your boat for the winter.


However, you also need to consider how often you use your boat. Ideally, replace your spark plugs every 75 to 100 hours.



Inspect the Thermostat


The thermostat is often under-appreciated. It is vital to regulate the water temperature and pressure in the cooling system.


The cooling system is what helps dry the heat away from the pistons in the shaft. If the water temperature isn’t correct, the heat isn’t pulled away, and your engine won’t run right.



Replace Fuel Filters


Replacing your fuel filter is vital in your boat motor service list. The component will remove debris and water from the fuel before it reaches the inner workings of your engine.


You need to know what kind of engine you have in order to choose the right filter. Some motors will use a two-phase, two filter system.



Replace the Engine Oil Filter


Just like the fuel filters clean the fuel going into your engine, the oil filter is going to remove debris from the engine oil.


How often you change the filter depends on how many hours you put on your engine.



Replace Lower Unit Oil and Inspect or Water in the Lower Unit


You will need clean oil to protect the gears in your lower unit. Water is the enemy of your boat motor, so check for it while you are replacing the oil.



Pressure Test the Lower Unit


Testing the lower unit pressure is going to require a specific gauge that is compatible with your boat engine.


The mechanic performing your outboard engines maintenance will have these tools.



Install a New Water Pump


This is the pump that circulates the fresh water around your engine to draw heat away and cool the engine. It needs to be checked for any possible debris that is blocking the flow of water through the system.



Remove the Prop and Inspect the Seal


If you see milky colored oil coming from the lower unit, you need to replace the prop shaft seals.


The process is relatively straightforward, but it will be time-consuming and require you taking apart a lot of pieces.



Replace the Zinc


This is another part of your engine where it pays to have a professional look at it. If you do a quick visual inspection, you may assume the zinc looks good.


When you have two metals in the same saltwater, they have an electrical current between them. This causes them to corrode.


To prevent this, you need to introduce a third metal to the equation, such as zinc. This third metal sacrifices itself and corrodes instead of the other two.


The problem is that if you don’t replace the zinc, its integrity is compromised and won’t be as effective. This will cause the other metal to start to corrode.



Grease the Fittings, Prop Shaft, Drive Shaft, and Trim Steering


Greasing the fittings, prop shaft, drive shaft, and trim steering protects these elements from corroding. It also lubricates them so they can move smoothly.



Inspect the Poppet Valves


This valve is a part of the cooling system. It’s responsible for regulating the water pressure.


This mechanism moves to change the amount of water flow in response to the speed of the engine. Dirt and debris can cause the valve to stick and malfunction.



Protect against Corrosion


Saltwater is the ideal environment for corrosion. This is a problem when you’re trying to prevent corrosion while using your boat.


Using a CRC block will protect your motor and preserve the metals.



Inspect Steering Components


If you can’t steer your boat, you have no control over it. This creates a dangerous situation.


Most often, there is a cable that runs from the engine to the steering wheel. The cable and fittings need to be lubricated to protect them from corrosion and freezing up.



Outboard Motor Service


In case you’re winterizing your boat, plan to get it serviced. If you use your boat year round, take an honest look at the number of hours you are putting on your boat.


Schedule your outboard motor service with a reputable mechanic. Determine that they have experience with working on your particular boat engine.


Ask them what’s included in their annual boat maintenance checklist. Confirm with them that they’re going to cover the items that we have gone over here.


Schedule your annual outboard boat engine service today!

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