Most Common Problems with Suzuki DF140

When it comes to the best power-to-weight ratio, you will see the DF140 on top of the list.

After going through some forums and hearing user experiences, I have found out that the motor has some problems.

In this article, I have gathered almost all common problems with Suzuki DF140 outboard motor. 

ProblemsReasons
Motor making an intermittent clattering noiseFaulty tilt trim solenoidsLack of lubrication
Engine overheating Faulty sensorsBad wiring and connectionFilters not functioning properly
Surging issueVST filter (probable cause)
Engine mount corrosionBad design trapping exhaust gas

1. Motor Problems

The problem I am about to discuss is likely to happen in the older units. One particular user had a 2004 model. 

Even after 100 hours of use, the motor didn’t have any major issues. However, activating tilt/trim he started hearing an intermittent clattering noise. 

It more or less sounded like the mechanism was binding or sticking along several different positions. 

Also, the motor showed rough idle and vibration above 1500-2000 rpm.

Possible reason

According to another user, the problem might be at the ends of the rams where they meet the engine. It can be the lack of proper lubrication.

One needs to examine the issue further and try to identify whether it coming from inside the cowling. If yes, you will have to suspect the tilt trim solenoids.

Considering the second problem, it is normal to have slight vibrations at idle.

Possible fix

Apply some grease at the trim rods and it should take care of the problem.

In case, the problem continues, you may need to replace the solenoids. 

I have seen one user having the same problem but due to low voltage. So, changing the battery in this particular case solved it. 

2. Overheat Issues

It is possible to have overheating issues with the Suzuki DF140 engines. 

There is hardly any talk on this matter because it is not very common. If you are having this issue, my discussion will shine some light on it.

Possible reason

The troubleshooting involves several steps and checking various parts. 

First of all, check the oil cooler near the oil filter. It can be corroded or not working properly. Having bad seals can mix oil and water which is bad. 

After that, drop the lower units and check the status of the impeller. 

Next, examine the thermostats and exhaust sensor, and see whether they are working properly or not. At the same time, look for connection issues.

Check the plugs and make sure that there is no head gasket problem. 

Possible fix

Either you are getting a reading of overheating engine light and assuming that there is a problem or have seen it by manually checking. 

In both situations, you have to perform the checks mentioned above. If the problem is being fixed, check the hoses and pipes. Also, descale the motor.

However, those who are seeing overheating warnings on the dashboard should check the sensors first. 

It is the smartest thing to do. 

Because after hours of troubleshooting and replacing several parts, you may see that one sensor is not working properly and causing the alarm.

3. Surge Issue

Another common problem with Suzuki DF140 is the surging issue. Some of the users have complained that their motor suddenly catches air and briefly drops the RPM.

After hopping back up to WOT for about 20 seconds, the motor operates 500-600 RPM lower.

When you throttle back from WOT, the issue is no longer there. 

Sometimes, it gets so severe that the engine speed suddenly drops from 5500 RPM to 1500 RPM. 

Possible reason

Some experts suggest checking the intake screen at the VST. You can find it behind the intake manifold. 

You need to remove the manifold to gain access. 

Even running the boat on a remote tank and using a new primer bulb may not solve the issue. 

It is hard to pinpoint the reason for this problem. You can take the trial-and-error procedure to solve it.

Possible fix 

You can replace the fuel lines, and change the low-pressure and high-pressure filter. 

Also, you should drain the fuel rail and cooler. Clean the VST, replace the filter of the VST, and run the engine again. 

Disclaimer: Those are not 100% accurate procedures to solve the issue. You should take the advice of a mechanic if trial-and-error is not your forte. 

4. Corrosion Problems

Some users have complained that the ports of the engine mount are prone to rust.

Having such a corrosion problem can cause several issues. For example, it can blow a hole in the port destroying the wiring harness.

Possible reason

One of the dealers of Suzuki DF140 mentioned that bad design caused the exhaust to be trapped.

As a result, the metal parts are getting rust even though it is not supposed to be. In severe cases, the starboard engine can also get damaged.

Possible fix

To solve the problem, you have to take the engine to the dealer or call a boat mechanic. 

They can make the necessary adjustments. And, replace the rusted parts. 

Another alternative to replacing the rusted parts is to use JB Weld or Mighty Putty.

What Majority of the Users Feel About Suzuki DF140?

Despite very few problems and complaints, there is nothing bad about DF140 outboard motor. 

Considering the price, features, and performance, it is one of the best in its category.

According to its first-hand users, the motor is quiet and has better fuel efficiency. 

Installing it on the back of a 19′ Whaler outrage in Avalon can give you the expected speed.

However, the 2.0L Suzuki 140 is a bit heavier compared to other similar products. And, the output power feels like 125-130 HP although it has a 140 HP engine.

For those who have a tight budget, 140 is a decent motor and worth investing in.

Final Thoughts 

Some of those problems are very common in almost all of the units. For example, the corrosion issue occurs in every older unit of DF140. 

But that should not stop you from buying the motor. Because it has a very powerful engine with reliable performance. 

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