Stihl MS 391 Problems, Troubleshooting With Solutions

Stihl ms 391 is a high-performance chainsaw with many fantastic features. Unlike other tools, it cares about your safety. The saw can handle big and thick trees, and it can cut diagonally.

However, like any other great saw or product, this model doesn’t free from some problems. Yes, you might face some issues while using it.

Some common problems of Stihl ms 391 are starting problems, suddenly losing power, oil tank leaking problems, dirty air filter injuries, and so on. These problems might occur from time to time and decrease your efficiency.

But don’t worry, man, as I have also laid out some fantastic tips for those problems. So, you can check out those to fix those problems on your own! So, let’s get started.

List of Stihl MS 391 Problems (With Solutions)

Throughout the section, I’ll list all the different problems ms 391 shows. Will not only show the list but also share why the problem is occurring and what steps you can take to resolve those.

Sounds good; let’s check it out!

Confused about 391? Check out the comparison: Stihl MS 391 Vs 362: Which Is Better?

1. Stihl MS 391 Starting Problems

There are a few issues that can cause starting problems. Generally, you face starting issues when there are problems with three things. They are spark, fuel, and compression.

Stihl MS 391 Starting Problems


So, how to fix the issue? You need to check spark, fuel, and compression to do so. Let me show you how.

Ground the plug against the metal cylinder head to check if the spark is working. Check to see if the sparks don’t appear. Coils and ignition modules can also fail, so a spare spark plug is worth putting in any case since spark plugs fail, too.

And to check fuel? You can try starting the carb by squirting some fuel into it. You need to investigate fuel lines, carburetors, etc. if it still fires after that.

When it comes to Compression? If you can’t get a proper tester, pick up the saw by its starter cord; if it spools out and lowers itself to the ground, it has severe internal injuries. Another simple check is to remove the muffler and inspect the side of the cylinder. It’s up to you if it’s poorly done.

2. The Chain Has Stopped Engaging Due to a Dirty Air Filter.

The air filter is a critical part of the chainsaw, used to prevent debris from entering the engine. You’ll notice reduced power and poorer cutting performance when it becomes clogged. 

Dust accumulation on the inside and outside of your chainsaw can exacerbate this issue if you don’t use it enough. It’s essential to regularly clean all surfaces of your tool, including its air filter.

Chain Has Stopped Engaging Due to a Dirty Air Filter


To ensure that everything stays in tip-top shape for as long as possible, replace your air filter at least once a year; if multiple users share one machine, then make sure everyone knows when it needs replacing so, they aren’t surprised when things stop working correctly!

3. Chainsaw Suddenly Lost Power

The Stihl ms 391 might suddenly lose its power. This is a serious problem and can’t be said what you are engaged in at the time. Power failure will immediately stop the engine and interrupt the chainsaw’s rotation. This might lead to severe accidents if you are engaged in heavy woodworking projects.

Chainsaw Suddenly Lost Power


The problem might occur due to several reasons. Check if you are using old oil and Mobil. If so, change it. Figure out if there is any air leakage. You could remove the muffler and have a grander piston if you take the muffler off. Make sure you fix these problems.

4. Chain Sprocket and Clutch Drum Oil Seal Failure

This is the most common problem for these chainsaws. It is caused by the chain being too tight and rubbing against the sprocket and the clutch drum. This causes excess friction, which then causes heat and other problems.

Chain Sprocket and Clutch Drum Oil Seal Failure


So, how to fix chain sprocket and clutch drum oil seal failure? Well, the fix is easy, super easy than you might think!

All you need to do is loosen your chainsaw.

Related: Common Husqvarna 465 Rancher Problems and Solutions

5. Crankshaft Oil Seal Failure

The crankshaft oil seal can fail because of improper assembly or use. This can stop the engine.

Crankshaft Oil Seal Failure


Check to ensure your oil seal is seated properly during assembly, and don’t use too much torque when installing it. Also, check that your oil pump is working correctly. The spindle will not rotate appropriately if there is insufficient pressure, which can lead to this problem.

6. Poor Handling

The ms 391 has a lot of power and torque for its size, but it can be challenging to handle if you don’t know how to use it properly.

Poor Handling


Make sure you have sound footing before operating your chainsaw, especially if you use an extension pole or ladder stand. Don’t try cutting through anything thicker than 4 inches while standing on a ladder!

7. Leaking Oil Tank

The leaking tank problem is common on Stihl chainsaws, primarily when used heavily or over long periods (typically more than ten years). The leaking tank problem can also be caused by bad O-rings or seals inside.

Leaking Oil Tank


Regularly cleaning and checking for leaks would be the solutions and prevention for the problem.

How Much Is a 391 Stihl Chainsaw Worth?

MS 391 chainsaws are among the most popular on the market today. It is a reliable, powerful, and efficient machine. It has been in production for over 30 years, and its popularity is still strong.

How Much Is a 391 Stihl Chainsaw Worth

Starting at $599, the MS 391 Stihl chainsaw goes up to $999. Several features make the MS 391 a worthwhile investment, including its chain brake system, which prevents the bar from spinning at maximum speed, a chain oiler, which lubricates the chain during operation, and a low-friction piston head.

Separately available accessories for the MS 391 are also impressive.

Read more: Stihl 311 vs 391

Is a STIHL MS 391 a Pro Saw?

A pro saw is a saw with a high-quality blade designed to cut through hardwood and other dense materials. The STIHL MS 391 has a high-quality blade that can cut through hardwood and other dense materials.

Is a STIHL MS 391 a Pro Saw

The STIHL MS 391 has been rated as one of the best pro saws on the market, according to its features and price.

The STIHL MS 391 is a professional-grade saw with excellent performance in cutting wood and other dense materials. It has an ergonomic design with a comfortable grip for increased control during use. It also has an easy start system, making it easier for users to start the machine quickly.

How Big of a Bar Can You Put on a Stihl MS 391?

Thanks to its robust, versatile, and reliable design, it can handle various applications. The ergonomic design and high-quality materials make it comfortable to use.

How Big of a Bar Can You Put on a Stihl MS 391

For any outdoor application, the STIHL MS 391 is the perfect tool. Trees and brush can be cut down with a powerful engine. In addition, it has a manual throttle control that allows you to control the power and speed of your cutting when you need it. 

While cutting down trees or brush, you can choose the length of your bar and how much weight you want to carry.

Is the Stihl Ms 391 a Good Saw?

The Stihl ms 391 is a powerful and lightweight saw that can be used for various tasks.

The MS 391 makes up for it with its cutting speed and style. The saw has a cutting speed of 6,000 per minute, which is plenty fast for cutting through any piece of wood or other material you may need to cut. The saw is also designed with a vibration reduction feature that allows the user to control the vibrations of the saw and keep them from interfering with their job.

Is the Stihl Ms 391 a Good Saw

The chainsaw is ideal for homeowners who need to cut down trees or branches in their backyard or for contractors who need to work on small projects with extensive power tools.

The only downside is the weight. This model may not be your best choice if you’re looking for a lightweight but powerful saw.


So, we have got to the end of the post, and I have discussed everything you need to know about Stihl MS 391 problems.

From the causes of the problems to the solutions, I tried to provide you with the best resources possible, yet if you got any queries., feel free to let me know in the comments.

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