When an outboard motor is functioning well, it will be able to perform flawlessly at all modes of usage.
This includes performing well at the idle mode and also performing well when throttling or accelerating.
But sometimes an outboard motor idles but bogs with throttle or acceleration.
When this occurs, it is usually due to a problem of power generation from the outboard motor.
When an outboard is in an idle mode, it uses less power.
But when it is accelerating or throttling, then the power demand from the outboard motor will increase.
If the outboard motors performance is not up to the increasing power demand, it will start to show negative signs like vibrating, bogging or even stalling.
This is one of the reasons why an outboard motor loses power when throttling or accelerating.
some of the reasons why this occurs is the use of bad fuel line, use of bad spark plug, faulty fuel pump, faulty carburettor, overloading and faulty ignition system.
A failure in most of these outboard motor components will also reduce the performance of the outboard motor.
Why Outboard Motor Idles But Loses Power When Throttling Or Accelerating
1)Bad Fuel
Apart from the components of an outboard motor, one of the most important things that makes an outboard motor to function is the fuel in it.
With fuel in an outboard motor, combustion will be able to take place in the combustion chamber.
When combustion takes place in the combustion chamber, power is released from the outboard motor.
But this level of power released from the outboard motor depends on the quality of fuel used.
If you use a good quality of fuel in running the outboard motor, the performance of power generated will be able to push the boat effortlessly.
But if a bad quality or contaminated fuel is used, the performance of the outboard motor will reduce.
Solution
a)Use Good Fuel Quality
When making use of your outboard motor you want to get the best performance out of it.
But for this to be possible, you have to be very careful of the components of the outboard motor as well as the type of oil you use in the outboard motor.
That is why you have to make sure that you always use a good quality of fuel in your outboard motor.
This will help the outboard motor in achieving a good level of performance.
2) Use Of Bad Spark Plug
For the outboard motor to produce power, ignition has to take place in the combustion chamber.
But for an ignition to take place in the combustion chamber, the spark plugs has to ignite the fuel mixture.
This is when the spark plug delivers a supercharged voltage that is receives from the ignition coil to help ignite the fuel mixture in the combustion chamber.
With this, the outboard motor will be able to generate power for use in pushing the boat in the direction the boat operator desires.
But when a bad spark plug is being used in the outboard motor, then the outboard motor will not be able to perform well.
This will really show up when accelerating or throttling to a higher speed.
Solution
a)Use Good Spark Plugs
If you discover that the outboard motor is running with a bad spark plug, you have to make sure that you change the spark plugs.
In making a change of the spark plugs, make sure that you make use of a good spark plug.
This will help in increasing the performance of your outboard motor.
b) Use Good Fuel To Oil Mix Ratio
Most times when a spark plug is not performing well, it is not because the spark plug is totally bad.
One of the reasons why a spark plug will not perform well is when it is covered with oil or carbon.
This is usually due to the use of a wrong mix ratio especially in a 2-stroke outboard motor.
To avoid this, you have to make sure that you use a good mix ratio in running your outboard motor.
This is why using one of the best fuel to oil mix ratio in running your outboard motor which is 50:1 will always give a good performance.
3) Faulty Fuel Pump
The fuel pump plays a very vital role when it comes to the performance of an outboard motor.
This is because the fuel pump helps in delivering fuel from the gas tank to the carburettor at the right pressure.
If the fuel pump is bad, then delivery of fuel from the fuel tank to the carburettor will be negatively affected.
This will lead to less volume of fuel for combustion in the combustion chamber.
As a result of this the performance of the outboard motor will be reduced.
Solution
a)Use a Good Fuel Pump
In running your outboard motor to achieve a good performance, you have to make sure that you use a good fuel pump.
This will help in delivering the right volume of fuel to the carburettor.
With this, the combustion chamber will be well fed with the right amount of fuel thereby leading to better power generation from the outboard motor engine.
b) Use Correct Fuel Pump Capacity
In running your outboard motor, you must not just use a good fuel pump.
You have to make use of a good fuel pump with the right capacity that is needed for that outboard motor.
This is what will ensure that the right volume of fuel is delivered to the carburettor for use.
If you use the lesser capacity of fuel pump to run your outboard motor, then the carburettor will receive a lesser volume of fuel.
You must also not make use of a fuel pump that is too large in capacity.
If the fuel pump capacity is larger than the need of the outboard motor, the outboard motor may still have issues in performance.
That is why it is important for you to make sure that you use the correct capacity of fuel pump in running your outboard motor.
To get this correct, make sure that you check for recommendation and specifications in the user manual of the outboard motor.
4) Faulty Ignition Coil
Another reason why outboard motor idles well but loses power when accelerating is due to faulty ignition coil.
For power to be generated in an outboard motor, combustion of fuel must take place.
But before the combustion of fuel mixture takes place, there are some components of the outboard motor that helps in achieving this.
One of these components is the ignition coil.
With the help of an ignition coil, a supercharged voltage is fully supplied to the spark plug.
This helps the spark plug to ignite the fuel mixture in the combustion chamber thereby releasing power.
But if the ignition coil in the outboard motor is not functioning well, the spark plug will not receive the required voltage to easily ignite fuel mixture in the combustion chamber.
This will directly lead to less power production from the outboard motor.
Solution
a)Use Good Ignition Coil
If you discover that the ignition coil in your outboard motor is not functioning well, you have to make sure that you replace it.
In replacing the outboard motor ignition coil, you have to make sure that you check for the recommended type that will fit your outboard motor.
With this an efficient level of combustion will be able to occur in the combustion chamber thereby generating power for use in the outboard motor.
5) Bad Fuel To Oil Mix Ratio
In a 2-stroke outboard motor one of the causes of less power production from the outboard motor engine is usually due to wrong fuel to oil mix ratio.
When you make use of a wrong fuel to oil mix ratio in running your 2-stroke outboard motor, the performance will not be as good as when you make use of a good mix ratio.
If the oil in the fuel is too much, then complete combustion will not take place in the combustion chamber.
This will lead to the outboard motor producing more smoke while it is running.
Apart from the outboard motor producing more smoke while it is running, the spark plug in the outboard motor will be fouled.
This will reduce the efficiency and power generated from the outboard motor.
Solution
a)Use Correct Fuel To Oil Ratio
For your outboard motor to perform well especially the two stroke outboard motor in which fuel has to be mixed with oil before adding the fuel to the fuel tank, you have to maintain a good mix ratio.
To ensure this, you have to use the recommended fuel to oil mix ratio for 2-stroke outboard motors which is 50:1.
With this the album motor will be able to perform well and produce more power.
6) Bad Carburetor
An outboard motor idles but loses power when accelerating if the carburettor is bad.
A carburettor helps in sending fuel that it receives from the fuel tank to the combustion chamber.
The combustion chamber will be able to use the fuel to produce power for use in the outboard motor through combustion.
But if the carburettor in the outboard motor is bad, it will not be able to supply the combustion chamber with the needed volume of fuel.
A bad carburettor can supply little to no volume of fuel to the combustion chamber which will lead to engine starving and less power production.
A faulty carburettor will also supply excess volume of fuel to the combustion chamber.
In a case like this in which the carburetor supplies excess volume of fuel to the combustion chamber, engine flooding will occur.
This will lead to poor power generation from the outboard motor.
Apart from less amount of power being generated from the outboard motor, smoking will also occur which can lead to spark plug fouling.
Solution
a)Use a Good Carburetor
In achieving a good performance from your outboard motor, one of the components in the outboard motor that you have to ensure that it is working well is the carburettor.
With a good functional carburettor, your outboard motor will easily perform well.
But if the carburettor is bad, the outboard motor will suffer performance lag.
To help correct this, you must make sure that you rebuild a carburettor or you buy a new replacement if the old one is critically damaged.
7) Overloading
An outboard motor idles but loses power when throttling due to overloading.
Every outboard motor has a maximum load it can comfortably move.
This is seen in the specifications of the outboard motor.
You cannot expect to move a 5,000 kg load with a 3 horsepower outboard motor.
This can easily destroy the outboard motor.
This is because the load is larger than what the outboard motor can comfortably carry.
Due to this, the outboard motor is going to lose performance.
That is why you have to make sure that you don’t overload your outboard motor if you want your outboard motor to perform flawlessly.
When maintaining the right load limit, situations in which outboard motor idles but bogs with throttle will rarely occur due to the load imposed on the boat.