When making use of your outboard motor, safety is very important.
This cuts across a lot of areas like always wearing your pfds and operating and not driving recklessly.
But concerning the speed, it doesn’t mean that you have to drive like a snail.
That is why an outboard motor not running at full power under load can be very disappointing.
This is usually caused by a lot of reasons.
Some of the reasons why outboard motors bog at full power under load include using a bad carburettor, using a bad fuel, using a bad fuel line, using bad spark plugs and other reasons like bad exhaust system.
When any of these problems set in, the performance of your outboard motor will reduce especially when you are accelerating.
Why Outboard Motor Bogs At Full Throttle Under Load
1)Bad Carburetors
When it comes to the functionality of an outboard motor, the role of a carburettor is very important.
For an outboard motor to function well, the engine has to be supplied with fuel.
But the volume of fuel applied has to be at a controlled rate.
This is because the volume of fuel consumed by the engine is always very different at different levels of functionality.
The carburettor then helps in making sure that it sends the right volume of fuel needed at a particular time.
But when the carburettor is bad, this will not be possible.
This flaw will really show up when you are accelerating.
This can be due to problems like float needle being stuck at a close position.
When a carburettor float needle is stuck at the close position, it will limit the volume of fuel that flows into the carburettor through the fuel line.
Due to this, the engine will have problems performing well due to low supply of fuel from the carburettor.
Another type of problems a bad carburettor faces is when it is clogged.
A carburettor can be easily clogged when it uses a bad fuel that contains debris in it.
That is why it is always very important to make sure that you use a good fuel in running your outboard motor.
Solution
a)Rebuild Carburetors
If you discover that your outboard carburettor is bad, you need to make sure that you fix it.
But in fixing your carburettor, you have to make sure that it can run at an optimal level after being fixed.
This is usually possible if the carburettor has minimal problems like a stuck float or loose drain screw.
One thing to consider when rebuilding your carburettor is to make sure that you get the rebuild parts from a reliable supplier.
This will help make sure that your outboard motor functions very well when you rebuild the carburettor.
b) Buy a New Carburetor
Rebuilding a carburettor is always one of the first decisions that some mechanics consider when a carburettor has a problem.
But this is never a good choice in some cases.
If you have a carburettor that is badly damaged, rebuilding may not really solve the problems of the carburettor.
This can be instances in which the carburettor bowl is critically damaged.
When a condition like this sets in, you have to make sure that you buy a brand new carburettor.
In buying a brand new carburettor, you have to make sure that you buy from a reliable and approved dealer.
In fixing the carburettor, you have to make sure that you use the services of a well experienced technician.
This will help bring your outboard motor to an optimal performance level again.
2) Bad Fuel
One of the most important things that keeps your outboard motor functional is the fuel.
Using a bad fuel is one of the reasons why outboard motors bog at full power under load.
Before your outboard motor can release power, combustion has to take place.
It is the fuel mixture that is ignited in the combustion chamber that helps generate power from the outboard motor.
But if you want to have a good performance, you have to make sure that you use a good fuel.
This will help achieve an optimum level of combustion to release power for use.
But if you have a bad fuel in your outboard motor, then the performance is going to suffer.
One of the ways this will show up is that your outboard motor will bog when accelerating under load.
Solution
a)Drain Bad Fuel
Running your outboard motor with a bad fuel is not good.
Due to this, the outboard motor will not be able to perform very well.
This can be due to using a fuel that has stayed for a long period of time without being used.
Fuel can also be bad if it contains water and dissolved particles.
When you discover this in the fuel used in running your outboard motor, you have to make sure that you drain it.
b) Use Good Fuel
If you have a problem with your outboard motor performance and discover that it is due to a bad fuel, you have to drain it.
After draining of the bad fuel,l you have to make sure that you fill in a good fuel before you run your outboard motor.
3) Incompatible Fuel Pump
Outboard motors not running at full power under load is common when the fuel pump is bad.
Fuel pumps are great components in an outboard motor.
They help deliver fuel from the fuel tank for use in the outboard motor.
But for them to work very well, they have to be able to deliver fuel at an optimum pressure.
Without this, the outboard motor will not be able to function well.
But when using a fuel pump in your outboard motor, you have to make sure that it is the right capacity.
This is because the level of fuel consumption in a 200 HP outboard motor can never be the same with that of a 3 horsepower outboard motor.
A 200 HP outboard motor will demand for more fuel for combustion than a 3 horsepower outboard motor.
If you use a 3 horsepower outboard motor fuel pump in a 200 HP outboard motor, then the engine will face starvation due to the inability of the smaller fuel pump to supply an optimum volume of fuel.
Solution
a)Use Correct Fuel Pump
In achieving a good performance from your outboard motor, the combustion chamber has to be well fed with the right volume of fuel.
To achieve this, the fuel pump plays a role.
That is why you have to make sure that you use the correct fuel pump capacity depending on your outboard motor.
4) Bad Spark Plug
Spark plugs are very important in an outboard motor.
This is because they are the final destination of charge delivery in an outboard motor.
For combustion to take place in the combustion chamber, a spark has to be delivered for the ignition of the fuel mixture to take place.
The delivery of this charge from the ignition system is usually achieved with the help of a spark plug.
If the spark plug is bad or partially working, then the rate at which fuel combustion takes place in the combustion chamber will be affected.
This will also affect the performance of the outboard motor.
This flaw will be very visible when the outboard motor is trying to accelerate under load.
At such a point, you will discover that the outboard motor will either be vibrating or bogging.
Solution
a)Use Good Spark Plugs
If you discover that your outboard motor is not performing well due to the use of a bad spark plug, you have to make sure that you change it.
When changing your outboard motor spark plug to a new one, make sure that you buy from a reputable supplier.
This will help your outboard motor to perform optimally when being used.
5) Overloading
Outboard motor not running at full throttle is also caused by overloading.
When making use of your outboard motor with your boat, you have to pay close attention to the load you carry.
This is because every outboard motor has a certain amount of load it can comfortably move.
If the Load imposed on the boat is higher than the capacity of the outboard motor, then you will face performance issues.
One of the issues that you are going to face is an outboard motor not running at full throttle under load.
Solution
a)Avoid Overloading Boat
To solve a problem that has to do with overloading of your boat, you have to make sure that you don’t overload your boat.
When imposing load on your boat, you have to also consider the capacity of your outboard motor.
If the load imposed on the boat is higher than the capacity that the outboard motor can carry, then you have to make sure that you reduce the load.
This will help you achieve a great performance when making use of your outboard motor.
6) Bad Exhaust System
When an outboard motor is functioning, the combustion chamber is always at a functional state.
This is what helps in achieving power generation from the outboard motor.
But after generating this power, it has to also send out some bye product.
This is usually the bye products from the combustion phase.
To send out these bye products, the outboard motor makes use of the exhaust system.
But if the exhaust system is not functioning well like being blocked, then the outboard motor performance will suffer.
Apart from affecting the performance of the outboard motor, a bad exhaust system in an outboard motor will also lead to poor fuel efficiency.
Solution
a)Fix Bad Exhaust System
When you discover that the exhaust system of your outboard motor is faulty, you have to try and fix it.
This should be done by an experienced technician to avoid complications.
7) Bad Ignition Coil
For an outboard motor to function well, then the parts and components in it have to also function well.
One of the parts in an outboard motor that plays a huge role in the performance of an outboard motor is the ignition system.
If the ignition system is bad, then the outboard motor will never be able to start.
This is due to the non production of electric charge for the combustion of fuel mixture in the combustion chamber.
But sometimes the outboard motor can still start if the problem in the ignition system is not too critical.
In such a situation, it will still suffer performance lag.
This can be due to the infunctionality of an ignition system components like the ignition coil.
The ignition coil is like a transformer in an outboard motor.
It helps in supercharging the electric charge that it receives before delivering it to the spark plug through the spark plug cap.
When an outboard motor is functioning, the combustion of fuel mixture is always in an active and continuous motion.
This also means that the ignition coil must also be delivering electric charge continuously to the spark plug.
But if the ignition coil is bad, then it will not be able to deliver the needed amount of electric charge for the spark plug to help ignite the fuel mixture.
This will affect the performance of the outboard motor especially when it is accelerating under load.
Solution
a)Replace Bad Ignition Coil
When you discover that you are having performance lag especially when you are accelerating your outboard motor, you have to perform a troubleshooting.
In troubleshooting your outboard motor, one of the parts you have to troubleshoot is the ignition system.
If during the troubleshooting you discover that the ignition coil is bad, you have to make sure that you change it.
In changing it you, you have to make sure that you changed it to a good one.
This will help your outboard motor to deliver and optimum amount of charge to the spark plug for an effective combustion to take place.
8) Stuck Propeller
The role of a propeller is very huge in an outboard motor.
It is what helps an outboard motor to give the final performance.
That is in moving a boat the outboard motor is placed on.
But sometimes it can have an issue that affects the overall performance of the outboard motor.
This is when it has problems like incompatibility or getting stuck.
When any of these problems set in, the outboard motor will not be able to perform very well.
This can be caused by seaweed restricting the free movement of the propeller.
Solution
a)Free Stuck Propeller
When you discover that your propeller is being stuck by things like seaweed, you have to make sure that you free it.
This will help your propeller to move freely and have a good and better performance.
b) Use Correct Propeller Size
In choosing a propeller for your outboard motor, you have to be very specific.
This has to do with the size of the propeller that you use in your outboard motor.
When you use the right size, you are going to have a good performance.
But when you use the wrong size of propeller in your outboard motor, the performance of your outboard motor will suffer.
That is why you have to use the right propeller size all the time.
9) Bad Fuel Line
The fuel line helps in sending fuel from the fuel tank for use in the outboard motor.
Sometimes it’s power can be neglected due to how small it is compared to other components of the outboard motor.
But if they develop a fault, the whole performance of the outboard motor will be totally affected.
This can happen when they have a cut or are clogged by debris.
When this occurs, the volume of fuel that is being sent from the fuel tank for use in the outboard motor will be extremely limited.
This will end up affecting the performance of the outboard motor.
a)Replace Bad Fuel Line
When you discover that the fuel line in your outboard motor is bad, you have to make sure that you fix it.
The fuel line is a component that is not really expensive but can seriously affect outboard performance when it is bad.
By fixing it, you have to make sure that you buy a good and reliable one.
This will help deliver the right volume of fuel to your outboard motor for use without obstruction.
10) Engine Problems
For your outboard motor to give an excellent performance, then your engine must also be at a top form.
That is why it is always important to regularly check the condition of your engine.
if your engine is performing well without flaws, then your outboard motor will also be able to perform well without extreme flaws.
But if the engine has a flaw or more problems, then the performance of the outboard motor will be greatly affected.
This can be due to an engine that is low in compression.
Whatever might be the problem of the engine, you have to make sure that you fix it when you discover it.
This will help your outboard motor to perform well when you are using it.
11) Overheating
When making use of your outboard motor it has to run at an acceptable temperature range.
This will help other components like the oil in the outboard motor to perform well.
But if your outboard motor is running at a temperature that is out of the performance temperature range of the outboard motor, then you will have performance issues.
This can show up when your outboard motor is overheating.
An overheating outboard motor is always caused by a cooling system that is not functioning well.
This can be caused by a failed impeller.
When you discover any of these faults, you have to make sure that you replace the failed part with a good one.
Solution
a)Fix Bad Cooling System
When you discover that the cooling system of your outboard motor is bad, you have to make sure that you fix it.
If the water flow is obstructed by a sea weed, you have to free the water hose.
But if the problem is very critical, you should consider replacing the cooling system with a new one.
12) Bad or Low Fuel Pump Pressure
An outboard motor bogs at full power when the fuel pump is bad.
The fuel system is very important for an outboard motor to perform well.
If it has some flaws, then the outboard motor will lag in performance.
A bad fuel pump is one of the reasons you have an outboard motor not running at full throttle under load.
When this happens, you have to troubleshoot.
One of the components you have to troubleshoot is the fuel pump.
In troubleshooting the fuel pump, you have to check the pressure at which the fuel pump is releasing fuel.
If it is too low, then you know that it is faulty.
Solution
a)Replace Bad Fuel Pump
If you discover that the fuel pump in your outboard motor is bad, you have to replace it.
In doing this, you have to make sure that you replace it with the correct fuel pump capacity.
If you replace it with a lesser capacity, you will starve your outboard engine of fuel.
This can lead to stalling or vibration when accelerating.
If you replace it with a fuel pump that is too high in capacity, engine flooding will occur.
This is why it is very important to replace a bad fuel pump with the correct one.
This will help the outboard motor to perform well.
Conclusion
Outboard motor not running at full power can be very frustrating especially when it is a commercially used boat.
When this occurs, you have to perform a troubleshooting to determine what is causing the power lag.
When you discover the cause of the problem, make sure you fix it early.
This will return your outboard motor to a good performance level and avoid outboard motor bogging when throttling.
Further Readings