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How to Adjust Idle Speed on Johnson Outboard? – Get Into World of Boat Knowledge

Johnson Outboard Adjusted Idle Speed

Imagine you are having fun at a cruise and wanted to set the boat at an idle speed?

But you could not due to not knowing how to adjust the idle speed on the outboard?

It is excruciatingly painful while all you want is to relax.

So, naturally, you need to know how to adjust the idle speed on the Johnson outboard?

So, how to adjust idle speed on Johnson outboard?

To adjust the idle speed, firstly you need to start the engine. Then, turn the idle screw as after locating it.

You will see a screw surrounded by a spring, that is the idle screw.

Also, you will find the screw slightly lower in your Johnson outboard motor. Turn the screw counterclockwise.

Ensure rotating to 1 and one-fourth.

Sounds informative? Then what are you waiting for? We have brought you detailed and comprehensive instructions on this.

So, hop on and get into the world of boat knowledge.

What Are Outboard Motors?

Outboard Motors

Before controlling its speed of it, we need to understand what it does. Outboard motors usually control the rotation of the propellers. Or the speed of the boat.

On top of that, the Johnson outboard is usually used for relatively smaller boats. You can find them, especially on fishing boats.

They are responsible for controlling the steering of the boat.

You can directly change the direction of the boat with the outboard motor. The thrust can also be controlled by the outboard motor as well.

Generally, you will find it installed at the transom.

The transom can commonly be found at the back of the board. Its primary objective is to push the boat in the water.

Therefore, a thrust is created, and the rotation of the propeller increases.

The Advantages of Outboard Motors

There are a couple of advantages of using outboard motors. Among them, the biggest one is the minimalism in their maintenance.

It can be fixed by a bolt at the back of the stern of the boat, also, it is a single machine. Essentially, making the installation process much easier.

Although, it is a bit old technology in retrospect of stern-drive engines. Also, Mercury outboard motors face fuel pump problems as well.

Stern-drive engines are becoming the preferred choice for the consumers for their modern features. Also, strict regulation on boat engines is also fading the outboard motors.

But these regulations are relatively lenient. Therefore, you can use it to this day.

Furthermore, it is also cost-efficient.

Materials Needed to Adjust Outboard Motors

Materials For Adjust Outboard Motors 1

Even though it might sound complicated, adjusting outboard motors needs only two things. They are easily findable in addition to being cost-efficient. Those are;

  • Screwdriver
  • Tachometers

This is essentially what you need to adjust your outboard motors. These are fairly easy to find. You can get them in any hardware store near you.

Procedure on Adjusting the Johnson Outboard Motors

Now we know what outboard motors are and what advantages they have. Now we need to look at the procedures for adjusting it.

Let’s dive into the procedures;

Step 1: Turn the Engine On

This is something you need to ensure first. The engine has to be turned on. The mechanism that turns a device on depends on your yanking mechanism.

Also, ensure that your trigger is not showing any symptoms of breaking.

If you use the key, then set it to neutral. Using a key is the most preferred method that everyone uses.

Check if the propeller has completely stopped working. Also, it’s better if you do it in a relatively stable stream. If the boat remains stationary, the workflow will be much more fluid.

Step 2: Check if It is Idling Properly

Turn the Idle Screw on Johnson boats

If you are to measure the correct idling rate, that varies from one engine to another. Since our discussion is on Johnson’s outboard engine, we will capitalize on that.

Even with the Johnson engine, the idling RPM rate varies.

It depends on the unit-to-unit of the engine. But on average, 600 RPM to 800 RPM is the ideal idle position for Johnson outboards.

If Your boat fails to be in the idle state, you will see a fluctuation in the RPM than stated. In that case, adjusting it is the best solution.

Step 3: Turn the Idle Screw

You will need to rotate the idle screw while having the engine turned on. You will see a spring surrounding it. In most Johnson boats, you will find it at the lower side of the outboard motor.

Rotate it counterclockwise. Give it one turn or maximum add another one-fourth turn to it.

Step 4: Keep on Listening While Turning

Once the above-mentioned procedure is completed, keep on turning more. Make sure to do it counterclockwise. At one point you will hear that the engine is drying out.

Drying out is caused by having an unprecedented amount of fuel and air in the mixture. As the engine dries out, start rotating the screw in a different direction than the previous one.

Keep on turning until the amount of air in the mix becomes excessive. You can ensure that by backfiring and stuttering sound.

Don’t worry if you feel like the engine will stop. It won’t. And even if it does, you can fix drowned outboard engines.

From this point. Again loosen up the screw or rotate it counterclockwise. But don’t do it too much. Rotate the screw from ½ to ¼ of a single rotation.

And voila! Your Johnson outboard’s idle speed has been adjusted. Now observe how your boat behaves.


Outboard Motors faqs

What RPM should an outboard idle at?

In order to have a high idle, you will need a high RPM. Also, you will need to figure out at what RPM your boat idles.

The number of RPM varies from boat to boat depending on their unit. But ideally, 600 to 800 RPM is the average RPM for the outboard idle.

How fast is Idle Speed on a boat?

At idle speed, you should always maintain a ‘no wake zone’. It is a regulation that is imposed by the state and federal governments.

In that regulation, the captain has to observe the slowest-possible vessel speed to maintain steering. The limit is 5MPH. You can not go higher than that.

How do you adjust the throttle on an outboard motor?

Again, start the engine. While having the engine turned on, twist the throttle grip. And rotate it counterclockwise. Rotate counterclockwise if you want to increase speed. And rotate clockwise if you want to decrease speed.

What RPM should a 2 stroke outboard idle at?

There is some debate on whether or not high idle on an outboard engine can cause any damage.

However, the consensus seems to be that it’s not likely to cause any serious problems.

In fact, many experts say that high idle can actually help protect the engine from wear and tear.

The main concern with high idle is that it can lead to overheating. Overheating can damage the engine internals, which could eventually lead to a breakdown.

However, in most cases this isn’t going to happen overnight – it will take a while for the engine to reach a point where it starts breaking down.

So, overall, it seems that high idle on an outboard engine isn’t really going to cause any major problems.

Unless you have a very specific reason to avoid it, you should probably just stick with normal idle settings.

Does idling burn oil?

There is some debate over whether or not idling burns oil. However, the majority of experts believe that it does.

When your engine is idling, the fuel is constantly being injected and burned, which can lead to decreased oil life and potentially even a fire.


So that’s all from our end. I hope now you know all you need to know on how to adjust the idle speed on the Johnson outboard.

These are some of the essential daily necessities you need to know if you own a boat. But always be careful. As you might have to work with electricity, it’s advised to be safe.

And if you are not confident, just call a professional. They might do a better job at repairing it.

So, Till then, Good luck with your Johnson outboard motors!

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