Can you start a Stihl MS 250 chainsaw without difficulty? Yes, by following a few simple steps, you can easily start your Stihl MS 250 chainsaw. This guide will walk you through the entire process, from preparing the chainsaw to the actual starting sequence. We’ll cover everything you need to know to get your Stihl 250 running smoothly for the first time and for future use.
Getting Your Stihl MS 250 Ready to Go
Before you can even think about starting your Stihl MS 250, it needs to be properly prepared. This preparation is crucial for both safety and the longevity of your chainsaw. Think of it like getting your car ready for a trip – you check the fluids, tires, and make sure everything is in order.
Fueling Your Chainsaw Correctly
The right fuel mixture is absolutely essential for a two-stroke engine like the one in your Stihl MS 250. Using the wrong mix can lead to serious engine damage.
Stihl MS 250 Fuel Mixture:
Stihl recommends using a high-quality, ethanol-free gasoline with a minimum octane rating of 89. You’ll mix this gasoline with a specific two-stroke engine oil designed for air-cooled engines. The standard Stihl MS 250 fuel mixture ratio is 50:1. This means for every 50 parts of gasoline, you add 1 part of Stihl two-stroke oil.
- Example: For 1 gallon (128 ounces) of gasoline, you would add 2.56 ounces (128 / 50) of Stihl two-stroke oil.
It’s best to use a dedicated fuel mixing container. This helps ensure you get the ratio right every time. Mix the fuel and oil thoroughly before pouring it into the chainsaw’s fuel tank. Always use fresh fuel; old fuel can lose its octane and degrade, causing starting issues.
Table 1: Fuel Mixing Ratios
| Gasoline Volume | Stihl 2-Stroke Oil Volume (50:1 Ratio) |
|---|---|
| 1 Gallon | 2.56 fl oz |
| 1 Liter | 20 ml |
| 5 Liters | 100 ml |
Checking and Filling the Chain Oil
Your chainsaw also has a separate oil tank for lubricating the guide bar and chain. This is vital to prevent overheating and wear.
- Locate the Chain Oil Tank: The chain oil tank cap is usually a different color or shape than the fuel cap.
- Fill with Bar and Chain Oil: Use a good quality bar and chain oil. Avoid using waste oil or motor oil, as these can clog the oiler and damage the chainsaw.
- Fill to the Max Line: Ensure the oil level is visible and up to the maximum fill line.
Inspecting the Chain and Bar
A sharp, properly tensioned chain makes starting and cutting much easier and safer.
- Chain Tension: The chain should be snug against the bar but still able to be pulled around by hand (with gloves on, of course). If it’s too loose, it can derail. If it’s too tight, it can cause excessive wear.
- Chain Sharpness: Dull chains require more force to cut and can strain the engine. If your chain looks blunt or you notice the wood chips are more like sawdust than shavings, it’s time to sharpen it.
The Stihl MS 250 Starting Procedure: Step-by-Step
Now that your Stihl MS 250 is fueled and ready, let’s get to the actual starting process. This Stihl MS 250 starting procedure is designed to be straightforward once you know the steps.
Step 1: Engage the Chain Brake
Safety First! Before you do anything else, always engage the chain brake. This pushes a lever forward, which stops the chain from moving. This is a critical safety step to prevent accidental chain rotation when starting.
Step 2: Activate the Stihl MS 250 Priming Bulb
The Stihl MS 250 priming bulb is a small, clear rubber bulb located near the carburetor. Its purpose is to push fuel into the carburetor to make starting easier, especially when the engine is cold.
- Locate the Bulb: Find the priming bulb.
- Press Repeatedly: Press the bulb several times (usually 3-5 times) until you see fuel return to the bulb. You should see the fuel moving. This ensures the carburetor has a fresh supply of fuel.
Step 3: Set the Choke
The Stihl MS 250 choke settings are crucial for cold starts. The choke enriches the fuel-air mixture, making it easier for the engine to ignite when cold.
- Identify the Choke Lever: The choke lever is usually a black plastic lever located near the air filter cover.
- Set to “Choke” or “Cold Start” Position: On most Stihl chainsaws, moving the lever upwards or towards the front of the saw engages the full choke. This is typically indicated by a symbol or the word “CHOKE” or a “cold start” position. For a cold engine, you want the choke fully engaged.
Step 4: Set the Master Control Lever
Your Stihl MS 250 has a master control lever that combines the choke, throttle lock, and stop switch.
- Disengage Chain Brake: Make sure the chain brake is still engaged for safety.
- Move Lever to “Start” Position: The master control lever needs to be in the “Start” position. On many Stihl models, this means the choke is engaged, and the throttle lock is also engaged. This prevents the engine from revving uncontrollably if it starts.
Step 5: Pull the Starter Rope
This is where you’ll actually try to start the engine.
- Firm Grip: Place the chainsaw on a firm, flat surface. Ensure it’s stable and won’t tip over.
- Hold Securely: With your other hand, firmly hold the top handle of the chainsaw to keep it steady.
- Pull the Rope: Grasp the starter rope handle. Pull the rope with a strong, steady motion. Don’t yank it. You’re trying to turn the engine over to get spark and fuel to meet.
- Listen for a “Pop”: You might hear a faint “pop” or a brief sputter from the engine. This indicates it’s trying to start.
Step 6: Move the Choke to the “Run” Position
If you heard that “pop,” it’s time to adjust the choke.
- Disengage Full Choke: Move the master control lever (which includes the choke) from the “choke” or “cold start” position to the “run” or “warm start” position. This typically means moving the lever down or towards the rear of the saw. The throttle lock will also disengage.
- Pull the Starter Rope Again: Pull the starter rope again, usually with less effort than the first pull. The engine should now start and run at idle.
Step 7: Let the Chainsaw Warm Up
Once the engine starts, let it run at idle for a minute or two. This allows it to warm up properly and ensures the Stihl MS 250 ignition system is functioning optimally. You can gently squeeze the throttle a few times to help it settle into a stable idle.
Step 8: Disengage the Chain Brake
After the engine has warmed up and is idling smoothly, you can disengage the chain brake by pushing the lever back towards the handle. Now your Stihl MS 250 is ready to use!
Starting a Warm Stihl MS 250
If your chainsaw has been running recently and is still warm, the starting procedure is slightly different. You generally don’t need the full choke.
- Engage Chain Brake: Always engage the chain brake.
- Prime the Bulb (Optional but Recommended): You can still give the Stihl MS 250 priming bulb a few presses to ensure fuel is present.
- Set Master Control Lever to “Run”: For a warm start, you typically set the master control lever directly to the “run” position (choke disengaged).
- Pull Starter Rope: Pull the starter rope firmly. The engine should start on the first or second pull.
Stihl Chainsaw Starting Tips for Easier Starts
Even with the correct procedure, sometimes a chainsaw can be a bit stubborn. Here are some Stihl chainsaw starting tips to help:
- Fresh Fuel: Always use fresh, properly mixed fuel. Stale fuel is a common culprit for starting problems.
- Clean Air Filter: A dirty air filter can restrict airflow and make starting difficult. Check and clean it regularly as part of your Stihl MS 250 maintenance.
- Spark Plug Check: Ensure the spark plug is clean, gapped correctly, and in good condition. A fouled or worn spark plug can prevent Stihl MS 250 ignition. You can check this by removing the spark plug boot, unscrewing the spark plug, and inspecting it.
- Carburetor Adjustment: If the chainsaw still has starting issues after checking these basics, the carburetor might need adjustment. This is often best left to a qualified service center if you’re not experienced with it.
- Correct Rope Pull: Pull the starter rope with a smooth, full stroke. Jerky or short pulls are less effective.
Stihl MS 250 Troubleshooting: When Starting Fails
What if your Stihl MS 250 refuses to start after following the procedure? Here are some common Stihl MS 250 troubleshooting steps:
No Spark
If the engine doesn’t even sputter, there might be an issue with the ignition system.
- Spark Plug: As mentioned, check the spark plug.
- Ignition Module: In rare cases, the ignition module itself could be faulty, preventing Stihl MS 250 ignition.
- Wiring: Check for any loose or damaged wiring connecting to the ignition system.
Engine Floods
If you smell a strong scent of gasoline, the engine might be flooded. This means too much fuel has entered the cylinder.
- Procedure: Move the choke to the “run” position (choke off). If the spark plug is accessible, remove it and clean it. You can also let the chainsaw sit for a few minutes to allow excess fuel to evaporate. Then, try starting again without priming.
No Fuel Reaching the Engine
If you don’t hear any sputtering and the Stihl MS 250 priming bulb seems to be working but no fuel is getting through, consider:
- Fuel Filter: The fuel filter inside the fuel tank can become clogged. This is a maintenance item covered in your Stihl MS 250 user manual.
- Fuel Lines: Check if the fuel lines are kinked or blocked.
- Carburetor: The carburetor itself might be clogged or faulty.
Air Filter Issues
A blocked air filter restricts airflow, preventing the engine from getting the necessary air to mix with fuel.
- Clean or Replace: Remove the air filter and clean it according to the instructions in your Stihl MS 250 user manual. If it’s damaged or heavily soiled, replace it.
Stihl MS 250 Maintenance for Reliable Starting
Regular Stihl MS 250 maintenance is key to ensuring your chainsaw starts reliably every time.
Routine Checks
- After Each Use: Clean the saw, check chain tension and sharpness, and ensure the oiler is working.
- Regularly: Clean the air filter, check the spark plug, and inspect for any loose parts.
Fuel System Maintenance
- Fuel Filter: Replace the fuel filter annually or as recommended in the Stihl MS 250 user manual.
- Fuel Tank: Keep the fuel tank clean. Avoid storing the chainsaw with fuel for extended periods. If storing for winter, it’s best to run it dry or use a fuel stabilizer.
Spark Plug Maintenance
- Cleaning and Gapping: Clean the spark plug every few months and check the gap. The correct gap is usually specified in your Stihl MS 250 user manual.
Frequently Asked Questions (FAQ)
Q1: What is the correct Stihl MS 250 fuel mixture?
A1: The correct Stihl MS 250 fuel mixture is 50 parts gasoline to 1 part Stihl two-stroke oil (50:1 ratio). Always use high-quality, ethanol-free gasoline and a dedicated two-stroke oil.
Q2: How many times should I press the Stihl MS 250 priming bulb?
A2: You should press the Stihl MS 250 priming bulb 3-5 times, or until you see fuel returning to the bulb. This ensures the carburetor is primed with fuel.
Q3: My Stihl MS 250 won’t start. What should I check first?
A3: First, check if you are using the correct Stihl MS 250 fuel mixture and that the fuel is fresh. Then, ensure the chain brake is engaged for safety, the choke is set correctly for a cold start, and you are pulling the starter rope firmly. For Stihl MS 250 troubleshooting, checking the air filter and spark plug are also crucial early steps.
Q4: What are the Stihl MS 250 choke settings for a warm engine?
A4: For a warm engine, you typically set the master control lever to the “run” position, which means the choke is disengaged. You usually don’t need the full choke for a warm Stihl 250 first start.
Q5: Where can I find the complete Stihl MS 250 user manual?
A5: You can usually download the official Stihl MS 250 user manual from the Stihl website. It’s highly recommended to read this manual before operating your chainsaw.
Q6: Is it normal for my Stihl MS 250 to require multiple pulls to start?
A6: For a cold start, especially in colder weather, it’s not uncommon to need several pulls. However, if it consistently takes many pulls even when warm, you might have a Stihl MS 250 troubleshooting issue to address, such as fuel delivery or ignition problems.
By following these detailed steps and tips, you’ll be well-equipped to start your Stihl MS 250 chainsaw easily and safely. Remember that proper preparation and regular Stihl MS 250 maintenance are the foundations for reliable operation.