Stihl MS 400 Review: Is the Magnesium Piston Worth It?

This Stihl MS 400 review covers my real experience with the world’s first magnesium piston saw. It was a crisp Tuesday morning. The air was cold, and I had a big job to do. A massive red oak tree had fallen in the back lot. It was about 24 inches wide.

My back was already stiff from working the day before. I looked at my heavy 70cc saw on the shelf. I did not want to lift it.

So, I grabbed the Stihl MS 400 C-M instead. I had heard the rumors. People said it was light but strong. I wanted to see if they were right.

Here is my honest story of using this saw.

Why This Saw is Special

Most saws have aluminum parts inside. The MS 400 is different. It is the first chainsaw in the world with a magnesium piston.

Why does that matter?

Magnesium is very light. A lighter piston can move faster. When you hit the gas, the engine should speed up right away.

I was not sure if I would feel the difference. I thought it might just be a sales trick. But then I started it up.

The “Snap” Test

I pulled the starter rope. The saw purred to life. I let it warm up for a minute. Then, I tapped the trigger.

Wow.

That is the only word for it. The response was instant. There was no lag. It has a “snap” that my other saws do not have. It felt eager. It reminded me of a race car engine. It just wants to go.

The Field Test: Cutting Oak

I walked up to that big oak log. I put on my helmet and chaps. Safety always comes first.

I pushed the 20-inch bar into the wood. Oak is hard. It usually slows a saw down. But the MS 400 just ate through it.

Here is what I felt:

• The Power: It pulled hard. It felt like a much bigger saw. It did not stop or stall.
• The Weight: This was the best part. It feels like a small saw in your hands.
• The Handling: It was easy to move. I could trim branches and cut the trunk. I did not have to switch tools.

After two hours, my arms were not tired. That is rare for me. Usually, I need a long break by noon.

Quick Specs Table

I made this chart for you. It shows the key numbers.

Living with the M-Tronic

This saw has the Stihl M-Tronic system. This means there are no screws to adjust the gas mix. The computer does it for you.

Some guys like to tune their own saws. I used to be like that. But on this cold day, I was glad I didn’t have to.

The air was thin and cold. The saw fixed the mix on its own. It ran smooth. I did not have to touch a screwdriver. That saved me time.

Pro Tip: If the saw acts funny, just reset it. Put it in the “start” position (the triangle). Let it run for 90 seconds. Then shut it off. It is that simple.

What I Did Not Like

No tool is perfect. I want to tell you the bad parts too.

• The Price: It is not cheap. You pay extra for the magnesium part. It is an investment.
• The Spikes: The metal teeth on the front are small. They grip okay, but I like bigger ones.
• Air Filter: It gets dirty fast. The saw cuts so fast that it throws a lot of dust. You need to clean it often.

Who Is This Saw For?

I sat on my truck tailgate when I was done. I looked at the pile of wood. I thought about who should buy this.

Buy this if:

• You cut a lot of firewood.
• You want one saw that can do it all.
• You want power but hate heavy tools.

Skip this if:

• You only cut small limbs (Get a cheaper MS 261).
• You are on a tight budget.

My Final Verdict

The Stihl MS 400 C-M surprised me. It is not a toy. The magnesium piston works. It is fast, light, and fun to use.

My back did not hurt at the end of the day. That alone is worth the money to me. If you can afford it, it is a joy to run.

Go to a dealer and hold one. You will feel the difference right away.

FAQs – Stihl MS 400 Review