Why Is 2 Stroke Outboard Motor Not Reaching Full RPM And How To Fix It Easily

When it comes to selection of an outboard motor there are a lot of things to consider before making the final decision.

Some people make use of outboard motor that do not really run fast.

This is common in personal outboard motors.

but some people make use of outboard motors that run very fast.

This is easily seen in commercially operated boats.

But sometimes even the fast moving outboard motors can have issues reaching full RPM.

An example of this is in a 2-stroke outboard motor not reaching full RPM.

Some of the reasons why a two-stroke outboard motor will not reach full speed is due to wrong fuel to oil mix ratio, carburettor problems, bad spark plug, bad exhaust system, overheating and having a loose throttle cable

When any of these parts or components have an issue reaching full speed while using your 2-stroke outboard motor, there will be an issue.

In this guide you will be shown how to easily solve these problems.

Why Is 2 Stroke Outboard Motor Not Reaching Full Speed

1)Wrong Fuel To Oil Mix Ratio

One of the big differences between a 2-stroke outboard motor and a 4-stroke outboard motor is how oil is used in the outboard motor.

In a four stroke outboard motor, the oil has a separate compartment.

But when it comes to a 2-stroke outboard motor, the oil is being mixed with the fuel before being introduced into the fuel tank.

This process has caused a lot of performance lag as far as making use of a 2-stroke outboard motor is concerned.

This is because when people make use of a wrong fuel to oil mix ratio, it will affect the performance of the outboard motor.

If the oil is too much in the fuel mixture, then you will have performance issues in which your outboard motor will be struggling to reach full speed.

Another problem you will have when oil is too much in your fuel mixture for a 2-stroke outboard motor is that the outboard motor will be releasing excess smoke.

If the volume of oil in the fuel mixture is too small then you will also have problems too.

The problem that you will have when the oil in the fuel mixture is too small is that your engine might knock due to poor lubrication of the moving parts in the engine.

That is why it is very important to make sure that you use the right mix ratio for your fuel mixture when making use of a 2-stroke outboard motor.

Solution

a)Use a Good Fuel To Oil Mix Ratio

To enjoy good performance from your outboard motors that is 2 stroke, you have to pay close attention to the fuel to oil mix ratio that you make use of.

Making use of the right mix ratio will always give you a very good performance.

This will help your outboard motor to still move and function easily when accelerating and avoid loss of power.

To achieve this, you have to make sure that you make use of the 50:1 fuel to oil mix ratio.

This will help your outboard motor to produce the needed power and also boost performance.

2) Carburetor Problems

A faulty Carburetor is one of the reasons why a 2 stroke outboard motor won’t reach full speed.

For an outboard motor to have a good performance, it has to function well when it has to do with combustion of the fuel mixture.

One thing that is very common in the use of an outboard motor is that it consumes different volume of fuel at certain condition.

When the outboard motor is in idle mode, it will consume less fuel.

But when it is running at a high speed especially when accelerating, then it consumes more fuel.

This fuel delivery to the combustion chamber is being controlled by the carburettor.

But problems will set in if the carburettor is not functioning well.

When this occurs, a faulty carburettor will not be able to send the right volume of fuel that is needed in the combustion chamber.

Due to this, the performance of the outboard motor will reduce drastically.

This even get worse when accelerating the outboard motor.

At such instance, you will discover that the outboard motor will be shaking or vibrating.

This is due to fuel starvation in the combustion chamber when the carburettor is not sending in the right volume of fuel needed.

Solution

a)Rebuild Carburetor

When you discover that your carburettor is having a problem in your 2-stroke outboard motor, you have to fix it.

One of the ways of fixing a bad carburettor is to make sure that you rebuild the carburettor.

In rebuilding the carburettor, you have to troubleshoot and know the exact problem of the carburettor.

If it has issues like a stuck float needle in the closed position, then you have to make sure that you free the float needle.

This will allow fuel to come into the carburettor and be released to the combustion chamber.

For a carburettor to be properly rebuilt, it has to be done by a very skilled technician.

The parts that will be used in the rebuilding process have to be genuine so that he can fit well and avoid further problems.

3) Bad Spark Plug

The spark plug is one of the ignition systems that helps a two stroke outboard motor in releasing power.

This is due to the role that the spark plug plays in a 2-stroke outboard motor.

With the help of a spark plug in a 2-stroke outboard motor, the fuel mixture is easily ignited in the combustion chamber.

This helps the outboard motor to produce power needed to move the boat in the right direction.

But if the spark plug is bad or partially functioning, then the ignition process in the combustion chamber will not be efficient.

This will lead to less power generation from the outboard motor engine.

Solution

a)Replace Bad Spark Plug 

When you discover that the spark plug that you use in your outboard motor is bad, you have to make sure that you replace it.

In doing the replacement, you have to make sure that you replace it with a good one.

This will help your outboard motor to produce the needed power especially when it is accelerating.

4) Bad Exhaust System

One of the reasons leading to 2 stroke outboard motors not reaching full speed is bad exhaust system.

For an outboard motor to easily generate power and perform well, it has to release the byproducts of combustion process.

This is usually gases and carbon.

But for these by-products to be released after combustion in the combustion chamber, the exhaust has to be functioning well.

What this simply means is that the exhaust has to give room for an easy release of the byproducts after combustion.

But in some cases, a faulty exhaust system will reduce how efficient these by products can be released.

When this occurs, the performance of the outboard motor will be poor.

This will be worse when you are accelerating the outboard motor.

Solution

a)Repair Bad Exhaust System

When you discover that the exhaust system in your two stroke outboard motor is not functioning well, you have to try and fix it quickly.

Fixing the problem of an exhaust system that is bad will help improve the performance of your outboard motor.

But before you try and fix a faulty exhaust system, you have to make sure that you troubleshoot properly.

This will help you pinpoint the exact component of the exhaust system that is causing the problem.

When you discover the exact problem, make sure that you provide a solution and solve it.

Having a good exhaust system will help in the easy release of byproducts of combustion and also help your 2-stroke outboard motor to perform well.

5) Overheating

Overheating can cause 2 stroke outboard motors not to reach full RPM.

When a two-stroke outboard motor is running, combustion is always actively taking place in the combustion chamber.

This creates a lot of heat in the process.

Without properly regulating this heat generated in the engine during combustion, the outboard motor can be easily damaged.

This is where the cooling system of the outboard motor comes in to avoid damage of the outboard motor due to extreme heat.

In a lot of outboard motors, water is being used to reduce the temperature of the outboard motor.

But for the water to be used in cooling the 2-stroke outboard motor, some components of the cooling system have a role to play.

These components includes an impeller and other components like the hose that will carry the water inside the outboard motor.

But as time goes on some of the cooling system parts may develop a fault.

When this happens, the effective cooling of the outboard motor to prevent overheating will not be possible.

Due to this, a 2-stroke outboard motor will easily overheat.

Solution

a)Repair Faulty Cooling System

When you discover that the cooling system of your outboard motor is not functioning properly, you have to make sure that you repair it.

if the impeller is the problem, then you have to make sure that you use a good impeller.

if you discover that the hose that transfers water is damaged or clogged with debris, then you have to make sure that you change the hose to a good one.

This will help in properly regulating the temperature of the two stroke outboard motor.

With this, overheating will be defeated in the 2-stroke outboard motor and performance will also increase.

6) Loose Throttle Cable

When making use of your 2-stroke outboard motor, the throttle cable tension has to be properly set.

If the tension of the throttle cable is set too high, you will have issues like a noisy outboard motor.

But making it too loose will also lead to problems.

That is why you have to make sure that you maintain an optimum tension level with your throttle cable.

If the throttle cable is loose, you will have problems reaching full speed when making use of your 2-stroke outboard motor.

Solution

a)Apply Good Throttle Cable Tension

In having an effective performance from your 2-stroke outboard motor, the throttle cable tension has to be optimally set.

If it is too loose, you will have problems reaching maximum RPM while using your 2-stroke outboard motor.

To avoid this, you have to properly tension the throttle cable.

This will help avoid 2-stroke outboard motors not reaching full RPM scenarios.

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