Stihl MS 400 C-M Review (5 Pro Tips For Lumberjacks)

As someone who has spent decades in the woods, the hum of a chainsaw is as familiar to me as my own heartbeat. I’ve seen chainsaws evolve from cumbersome, back-breaking tools to the finely tuned, high-performance machines we have today. But with that evolution comes a greater need for understanding how to properly use and maintain these powerful tools. That’s where the Stihl MS 400 C-M comes in. It’s a saw that demands respect, but rewards that respect with unparalleled performance. However, like any tool subjected to the harsh realities of logging and firewood preparation, wear and tear is inevitable. Understanding how to mitigate that wear and tear is crucial. This article is my attempt to share some hard-earned wisdom about maximizing the lifespan and performance of your Stihl MS 400 C-M, focusing on five pro tips that will help any lumberjack or serious firewood enthusiast get the most out of this exceptional machine.

Stihl MS 400 C-M Review: 5 Pro Tips for Lumberjacks

The Stihl MS 400 C-M is a professional-grade chainsaw designed for demanding tasks like felling medium-sized trees, bucking logs, and general forestry work. It’s known for its high power-to-weight ratio, thanks to its magnesium piston, and the M-Tronic engine management system that optimizes engine performance regardless of altitude, temperature, or fuel quality. This makes it a favorite among lumberjacks who need a reliable and efficient saw in various conditions.

Here are five pro tips to help you get the most out of your Stihl MS 400 C-M:

1. Mastering Proper Chain Sharpening: The Heart of Efficient Cutting

The single most important factor affecting a chainsaw’s performance is the sharpness of its chain. A dull chain not only slows down your work but also puts unnecessary strain on the saw’s engine and increases the risk of kickback. I’ve seen firsthand how a properly sharpened chain can transform a struggling saw into a cutting beast, and conversely, how a neglected chain can render even the most powerful saw useless.

Why Sharpening Matters:

Efficiency: A sharp chain cuts faster and cleaner, requiring less effort and fuel.
Safety: A dull chain is more prone to kickback, a dangerous situation where the saw can suddenly jump back towards the operator.
Saw Longevity: A sharp chain reduces stress on the engine and other components, extending the saw’s lifespan.

Step-by-Step Sharpening Guide:

Secure the Saw: Place the chainsaw in a vise or on a stable surface. Ensure the chain brake is engaged.
Choose the Right File: The Stihl MS 400 C-M typically uses a 3/16″ (4.8mm) round file for sharpening the cutters. Consult your owner’s manual for the specific file size recommended for your chain.
Set the Depth Gauge: Use a depth gauge tool to check the height of the depth gauges (also known as rakers) in relation to the cutters. The depth gauge controls how much the cutter bites into the wood. If the depth gauges are too high, the chain won’t cut effectively. If they’re too low, the chain will be too aggressive and prone to kickback. Typically, the depth gauge should be set to around 0.025″ (0.6mm) below the cutter. Use a flat file and a depth gauge tool to adjust the height of the depth gauges as needed.
Sharpen the Cutters:
- Angle: Hold the round file at the correct angle, typically 30 degrees for the cutting angle and 10 degrees for the down angle. These angles can vary slightly depending on the chain type, so refer to your owner’s manual.
- Stroke: Using a smooth, consistent stroke, file the cutter from the inside out. Apply gentle pressure on the forward stroke and release pressure on the return stroke.
- Consistency: Count the number of strokes you take on each cutter and repeat the same number of strokes on every cutter. This ensures that all cutters are sharpened evenly.
Sharpen the Depth Gauges (Rakers): If the depth gauges protrude too high after sharpening the cutters, use a flat file and a depth gauge tool to file them down to the correct height.
Check and Adjust: After sharpening, inspect the chain to ensure all cutters are sharp and evenly filed.
Lubricate the Chain: Apply bar and chain oil to the chain before using the saw.

Pro Tip: I’ve found that using a chainsaw filing guide can significantly improve the accuracy and consistency of your sharpening. These guides help you maintain the correct angles and depth, ensuring a more professional-quality sharpening. I personally use the Stihl 2-in-1 Easy File, which sharpens both the cutter and the depth gauge simultaneously. It’s a real time-saver and helps maintain the correct geometry of the chain.

Case Study: I once worked with a crew clearing a large tract of land for a new development. One of the sawyers was constantly complaining about his saw not cutting well, even though it was a brand new MS 400 C-M. After observing him for a while, I noticed that he was neglecting to sharpen his chain properly. He was just running the file across the cutters a few times and calling it good. I took the time to show him the proper sharpening technique, emphasizing the importance of maintaining the correct angles and depth. The difference was night and day. His saw started cutting like a hot knife through butter, and he was able to significantly increase his production.

2. Fueling with Precision: Optimizing Engine Performance

The Stihl MS 400 C-M, with its M-Tronic engine management system, is designed to run optimally with a specific fuel mixture. Using the wrong fuel or an incorrect oil-to-fuel ratio can lead to engine damage, reduced performance, and a shortened lifespan. I’ve seen countless saws ruined by improper fueling, and it’s a mistake that’s easily avoidable.

Understanding Fuel Requirements:

Fuel Type: Use high-quality unleaded gasoline with a minimum octane rating of 89 AKI (Anti-Knock Index). Ethanol blends are acceptable, but the ethanol content should not exceed 10% (E10).
Oil Type: Use a high-quality two-stroke engine oil specifically designed for air-cooled engines. Stihl recommends using Stihl Ultra HP two-stroke engine oil.
Mixing Ratio: The recommended fuel-to-oil mixing ratio for the Stihl MS 400 C-M is 50:1 (50 parts gasoline to 1 part oil).

Step-by-Step Fuel Mixing Guide:

Use a Clean Container: Use a clean, approved fuel container specifically designed for mixing fuel.
Pour Gasoline First: Pour the correct amount of gasoline into the container.
Add Oil: Add the correct amount of two-stroke engine oil to the gasoline. Use a measuring container or a fuel mixing bottle to ensure accurate measurement. For example, to mix 1 gallon (3.78 liters) of fuel at a 50:1 ratio, you would need 2.6 fluid ounces (77 ml) of oil.
Mix Thoroughly: Secure the lid on the fuel container and shake vigorously for at least 30 seconds to ensure the oil and gasoline are thoroughly mixed.
Label the Container: Label the fuel container with the date and the mixing ratio.

Pro Tip: I always mix my fuel in small batches, enough for only a few days of work. Fuel can degrade over time, especially if it contains ethanol. Storing fuel for extended periods can lead to gumming and deposits in the carburetor, which can cause engine problems. I also recommend using a fuel stabilizer, especially if you’re not going to be using the saw for a while. Fuel stabilizer helps prevent the fuel from degrading and keeps the carburetor clean.

Case Study: I once had a client who was experiencing frequent engine problems with his Stihl MS 400 C-M. He was constantly having to take it to the repair shop, and he was convinced that the saw was a lemon. After talking to him, I discovered that he was using a generic two-stroke oil that he bought in bulk from a discount store. I explained to him the importance of using a high-quality oil specifically designed for air-cooled engines and recommended that he switch to Stihl Ultra HP. He made the switch, and his engine problems disappeared. The saw ran smoother, started easier, and had more power.

3. Bar and Chain Maintenance: Extending the Life of Your Cutting System

The bar and chain are the workhorses of your chainsaw, and proper maintenance is crucial for optimal performance and longevity. Neglecting the bar and chain can lead to premature wear, reduced cutting efficiency, and increased risk of accidents. I’ve seen bars and chains worn out in a matter of weeks due to poor maintenance, and it’s a costly mistake.

Key Maintenance Tasks:

Chain Tension: Check the chain tension frequently, especially when the chain is new. A properly tensioned chain should have a slight amount of sag on the bottom of the bar and should be able to be pulled around the bar by hand. Too loose, and the chain can derail. Too tight, and it can bind and overheat.
Bar Lubrication: Ensure that the bar and chain are properly lubricated at all times. The Stihl MS 400 C-M has an automatic oiler, but you should still check the oil level frequently and ensure that the oiler is functioning properly. A dry bar and chain will quickly overheat and wear out.
Bar Cleaning: Clean the bar regularly to remove sawdust, dirt, and debris. Use a wire brush or a scraper to clean the bar groove and the oil holes. A clogged bar groove can prevent the chain from running smoothly, and clogged oil holes can restrict oil flow.
Bar Dressing: Check the bar for wear and damage. If the bar is worn, uneven, or has burrs, dress it with a bar dressing tool or a flat file. Bar dressing helps to restore the bar’s original shape and ensures that the chain runs smoothly.
Chain Rotation: Rotate the chain on the bar regularly to distribute wear evenly. This will help to extend the life of both the bar and the chain.
Chain Inspection: Inspect the chain regularly for damage, such as cracked or broken cutters, loose rivets, or worn tie straps. Replace the chain if it is damaged or worn beyond its service life.

Step-by-Step Bar Dressing Guide:

Secure the Bar: Place the bar in a vise or on a stable surface.
Inspect the Bar: Examine the bar for wear, damage, and burrs. Pay particular attention to the edges of the bar and the bar groove.
Dress the Edges: Use a flat file or a bar dressing tool to remove any burrs or sharp edges from the bar. File the edges of the bar at a slight angle to create a smooth, rounded edge.
Dress the Bar Groove: Use a bar groove cleaner or a small screwdriver to clean out the bar groove. Remove any sawdust, dirt, or debris that may be lodged in the groove.
Check for Straightness: Check the bar for straightness using a straightedge. If the bar is bent, it will need to be replaced.

Pro Tip: I always keep a spare bar and chain on hand. This allows me to quickly swap out a damaged or worn bar or chain without having to stop working. It also gives me the opportunity to clean and maintain the bar and chain while the saw is still in use. I also recommend using a high-quality bar and chain oil. Stihl bar and chain oil is specifically formulated to provide excellent lubrication and protection for your bar and chain.

Case Study: I once had a job cutting firewood for a large resort. The firewood was mostly hardwood, such as oak and maple, which is very abrasive and can quickly wear out a bar and chain. To extend the life of my bar and chain, I made sure to follow a strict maintenance schedule. I checked the chain tension and bar lubrication every time I refueled the saw. I cleaned the bar and chain at the end of each day. And I dressed the bar every week. By following this maintenance schedule, I was able to get significantly more life out of my bar and chain, saving me a lot of money and downtime.

4. Mastering Felling Techniques: Minimizing Stress on the Saw and Maximizing Safety

Felling trees is one of the most demanding tasks you can perform with a chainsaw. Improper felling techniques can put unnecessary stress on the saw, increasing the risk of damage and shortening its lifespan. More importantly, improper felling techniques can be extremely dangerous, leading to serious injury or even death. I’ve seen too many accidents in the woods caused by inexperienced or careless sawyers.

Key Felling Techniques:

Planning: Before you even start the saw, take the time to assess the tree and the surrounding area. Look for hazards, such as dead branches, power lines, or other trees that could be affected by the falling tree. Plan your escape route and make sure it is clear of obstacles.
Direction of Fall: Determine the natural lean of the tree and the desired direction of fall. Consider factors such as wind direction, terrain, and the presence of other trees or obstacles.
Notch Cut: The notch cut is a wedge-shaped cut that determines the direction of fall. It should be made on the side of the tree facing the desired direction of fall. The notch cut should be about one-third of the tree’s diameter.
Hinge: The hinge is a strip of uncut wood that connects the stump to the falling tree. The hinge controls the fall of the tree and prevents it from twisting or kicking back. The hinge should be about 10% of the tree’s diameter.
Back Cut: The back cut is made on the opposite side of the tree from the notch cut. The back cut should be made slightly above the bottom of the notch cut. Leave the hinge intact until the tree starts to fall.
Wedges: Use felling wedges to help guide the tree’s fall and prevent the saw from getting pinched. Insert the wedges into the back cut and drive them in with a hammer or axe.
Escape: As the tree starts to fall, move quickly to your planned escape route. Keep your eye on the tree and be prepared to react if it falls in an unexpected direction.

Pro Tip: I always use a felling lever when felling larger trees. A felling lever is a long metal bar with a pivoting foot that is used to lift and push the tree in the desired direction of fall. Felling levers can significantly reduce the amount of effort required to fell a tree and can help to prevent the saw from getting pinched. I also recommend taking a professional felling course. A qualified instructor can teach you the proper felling techniques and safety procedures.

Case Study: I once had a job felling a large oak tree that was leaning precariously over a house. The tree was very heavy and difficult to control. I carefully planned the felling operation, taking into account the tree’s lean, the wind direction, and the proximity of the house. I made a precise notch cut and back cut, and I used felling wedges to help guide the tree’s fall. As the tree started to fall, I used a felling lever to push it in the desired direction. The tree fell exactly where I wanted it to, avoiding the house and causing no damage.

5. M-Tronic Mastery: Understanding and Maintaining the Electronic Brain

The Stihl MS 400 C-M’s M-Tronic engine management system is a sophisticated piece of technology that automatically adjusts the engine’s fuel mixture and ignition timing to optimize performance in various conditions. While this system is generally very reliable, it’s important to understand how it works and how to maintain it to ensure optimal performance and longevity.

Understanding M-Tronic:

Automatic Adjustment: M-Tronic continuously monitors engine conditions, such as altitude, temperature, and fuel quality, and automatically adjusts the fuel mixture and ignition timing to optimize performance. This eliminates the need for manual carburetor adjustments.
Consistent Performance: M-Tronic ensures consistent performance regardless of environmental conditions. The saw will run smoothly and efficiently whether you’re working in hot, humid weather or cold, dry weather.
Simplified Operation: M-Tronic simplifies operation by eliminating the need for manual carburetor adjustments. You can simply start the saw and start cutting, without having to worry about fine-tuning the engine.

Maintenance Tips for M-Tronic:

Clean Air Filter: A clean air filter is essential for proper engine performance. A dirty air filter can restrict airflow and cause the engine to run lean, which can damage the engine. Clean the air filter regularly with compressed air or warm, soapy water.
Clean Spark Plug: A clean spark plug is also essential for proper engine performance. A fouled spark plug can cause the engine to misfire or not start at all. Clean the spark plug regularly with a wire brush.
Use Fresh Fuel: As mentioned earlier, using fresh fuel is crucial for optimal engine performance. Stale fuel can degrade and cause gumming and deposits in the carburetor, which can affect M-Tronic’s ability to properly regulate the fuel mixture.
Avoid Modifications: Avoid making any modifications to the engine or the M-Tronic system. These modifications can void the warranty and can potentially damage the engine.
Professional Service: If you experience any problems with the M-Tronic system, take the saw to a qualified Stihl service technician. Do not attempt to repair the system yourself.

Pro Tip: I always keep a spare air filter and spark plug on hand. This allows me to quickly replace a dirty air filter or a fouled spark plug without having to stop working. I also recommend using Stihl MotoMix pre-mixed fuel. MotoMix is a high-quality fuel that is specifically formulated for Stihl engines and contains a fuel stabilizer. It’s a bit more expensive than mixing your own fuel, but it can help to extend the life of your engine and prevent fuel-related problems.

Case Study: I once had a customer who was experiencing intermittent engine problems with his Stihl MS 400 C-M. The saw would start and run fine for a while, but then it would suddenly start to run rough and lose power. I checked the air filter and spark plug, and they were both clean. I suspected that the problem was with the M-Tronic system. I took the saw to a qualified Stihl service technician, and he diagnosed the problem as a faulty sensor in the M-Tronic system. He replaced the sensor, and the saw ran perfectly again.

Strategic Insights for Wood Processing and Firewood Preparation

Beyond the specific tips for the Stihl MS 400 C-M, there are broader strategic considerations that can significantly impact your overall wood processing and firewood preparation efficiency and profitability.

Wood Selection and Drying

Green Wood vs. Seasoned Wood: Green wood is freshly cut wood with a high moisture content (often above 50%). Seasoned wood has been dried, reducing its moisture content to 20% or less. Burning green wood is inefficient, produces less heat, and creates more smoke and creosote buildup in chimneys.
Drying Methods:
- Air Drying: The most common method, involves stacking wood in a well-ventilated area for 6-12 months, depending on the wood species and climate.
- Kiln Drying: A faster method that uses controlled heat and humidity to dry wood in a matter of days or weeks. Kiln-dried wood is more expensive but offers consistent moisture content.
Wood Species: Different wood species have different burning characteristics. Hardwoods like oak, maple, and ash burn hotter and longer than softwoods like pine and fir. However, softwoods ignite more easily, making them good for kindling.

Tool Selection and Optimization

Hydraulic Log Splitters: For high-volume firewood production, a hydraulic log splitter is essential. Choose a splitter with sufficient tonnage (20-30 tons is generally adequate for most firewood species) and a cycle time that meets your production needs.
Axes and Mauls: For smaller-scale firewood splitting, axes and mauls are still valuable tools. Choose an axe or maul with the appropriate weight and handle length for your strength and experience. A splitting maul with a wedge-shaped head is ideal for splitting large, knotty logs.
Chainsaw Selection: While the Stihl MS 400 C-M is an excellent all-around saw, consider having a smaller, lighter saw for limbing and smaller tasks. This can reduce fatigue and extend the life of your larger saw.
Personal Protective Equipment (PPE): Always wear appropriate PPE when operating a chainsaw or other wood processing equipment. This includes a helmet, eye protection, hearing protection, gloves, and chainsaw chaps.

Firewood Stacking and Storage

Proper Stacking: Stack firewood in a way that promotes good airflow. This will help the wood dry more quickly and prevent mold and rot. A common method is to stack the wood in rows, with gaps between the rows and between the pieces of wood.
Elevated Storage: Store firewood on pallets or other elevated surfaces to prevent it from absorbing moisture from the ground.
Covering: Cover the top of the firewood pile with a tarp or other waterproof material to protect it from rain and snow. However, leave the sides of the pile open to allow for ventilation.

Cost Analysis and Profitability

Track Expenses: Keep track of all your expenses, including fuel, oil, bar and chain maintenance, equipment repairs, and labor costs.
Calculate Production Rates: Determine how much firewood you can produce per hour or per day.
Set Prices: Set your prices based on your costs, production rates, and market demand.
Optimize Efficiency: Look for ways to improve your efficiency and reduce your costs. This could include investing in more efficient equipment, streamlining your processes, or finding cheaper sources of wood.

Next Steps

Now that you have a solid understanding of the Stihl MS 400 C-M and the broader principles of wood processing and firewood preparation, it’s time to put your knowledge into practice. Here are a few concrete steps you can take:

Review Your Owner’s Manual: Familiarize yourself with the specific recommendations and maintenance procedures for your Stihl MS 400 C-M.
Practice Sharpening: Dedicate some time to mastering the art of chain sharpening. Experiment with different techniques and tools until you find what works best for you.
Inspect Your Equipment: Conduct a thorough inspection of your chainsaw, bar, and chain. Identify any areas that need attention and address them promptly.
Plan Your Next Project: Choose a small-scale wood processing or firewood preparation project and put your new skills to the test.
Seek Expert Advice: Don’t hesitate to consult with experienced lumberjacks, arborists, or chainsaw technicians. They can provide valuable insights and guidance.

Remember, wood processing and firewood preparation are skills that take time and practice to master. Be patient, persistent, and always prioritize safety. With the right knowledge, tools, and techniques, you can transform raw wood into a valuable resource and enjoy the satisfaction of a job well done. And with the Stihl MS 400 C-M as your trusted companion, you’ll be well-equipped to tackle even the most demanding tasks.

Stihl MS 400 C-M Review (5 Pro Tips for Lumberjacks)