Can you start a Stihl MS170 easily? Yes, by following a few simple steps, you can get your Stihl MS170 engine started quickly and safely. This guide will walk you through the entire process, from initial setup to troubleshooting common issues.
Getting Your Stihl MS170 Ready: The First Start and Setup
Before you even think about pulling the starter cord, proper Stihl MS170 setup is crucial. This isn’t just about getting the saw running; it’s about ensuring it runs safely and efficiently for years to come.
Essential Components Check
- Bar and Chain: Ensure the guide bar is securely attached to the saw. Check that the chain is properly tensioned. A loose chain can fly off during operation, and a too-tight chain can cause excessive wear. To check tension, gently pull the chain away from the bar at its midpoint. It should spring back and remain snug against the bar but still be movable by hand.
- Oil: Your Stihl MS170 needs two types of fluids: fuel and bar oil.
- Fuel: This is a mix of gasoline and two-stroke oil. We’ll cover the Stihl MS170 fuel mixture in detail later.
- Bar Oil: This is a specialized oil that lubricates the chain and guide bar. It’s a thicker oil than the two-stroke mix. Ensure the oil reservoir is full. Without proper bar lubrication, your chain and bar will overheat, leading to rapid wear and potential damage.
Fueling Your Stihl MS170
The correct Stihl MS170 fuel mixture is paramount for the longevity and performance of your saw. Stihl recommends a mix of 50:1. This means for every 50 parts of gasoline, you need one part of high-quality two-stroke engine oil specifically designed for air-cooled engines.
Creating the Right Fuel Mix
Table 1: Stihl MS170 Fuel Mixture Ratios
| Gasoline (Liters) | Two-Stroke Oil (ml) |
|---|---|
| 1 | 20 |
| 5 | 100 |
| 10 | 200 |
- Use Fresh Gasoline: Always use fresh, unleaded gasoline with an octane rating of 89 or higher. Stale gasoline can cause starting problems and engine damage.
- Use Stihl Two-Stroke Oil: For best results, use Stihl’s own two-stroke oil or a high-quality equivalent. These oils are formulated to provide excellent lubrication and combustion in Stihl engines.
- Mixing: Use a clean, approved fuel container. Add the gasoline first, then add the oil. Secure the cap tightly and shake the container vigorously to ensure a thorough mix. Do not mix fuel directly in the chainsaw’s fuel tank.
Preparing for the First Start
Once your Stihl MS170 setup is complete and the fuel is mixed, you’re ready for the Stihl MS170 first start.
The Stihl MS170 Starting Procedure: A Step-by-Step Approach
Mastering the Stihl MS170 starting procedure is key to a hassle-free experience. Whether it’s a Stihl MS170 cold start or a Stihl MS170 warm start, these steps will guide you.
Step 1: Safety First!
- Clear the Area: Ensure the area around the chainsaw is clear of any debris, bystanders, or flammable materials.
- Stable Surface: Place the chainsaw on a flat, stable surface.
- No Load: Make sure the guide bar and chain are not resting on anything or anyone.
- Grip: Firmly grip the front handle with your left hand and place your left foot through the rear handle loop (or place your left foot firmly on the handle itself) to secure the saw. This prevents the saw from jumping or moving while you pull the starter cord.
Step 2: Engaging the Choke
The choke helps enrich the fuel mixture for starting a cold engine.
- Cold Start: For a Stihl MS170 cold start, push the choke lever completely in. You will hear and feel a click as it locks into the “cold start” position.
- Warm Start: If the engine is warm, the choke is usually not needed, or it might have a half-choke setting. If you’re unsure, and the saw was recently running, try starting it without the choke or with it in the neutral position.
Step 3: Activating the Master Control Lever
This single lever controls the choke, throttle lock, and run/stop positions.
- For Cold Start: With the choke fully engaged (pushed in), push the master control lever down. This will engage the choke and also set the throttle to a fast idle position, which is ideal for starting.
- For Warm Start: If the engine is warm, you can usually leave the master control lever in the neutral or run position. If it’s flooded, you might need to pull the starter cord with the choke disengaged (lever up) and the throttle slightly open.
Step 4: Priming the Fuel System (If Equipped)
Some MS170 models have a manual fuel primer bulb.
- Prime: If your saw has a primer bulb, press it repeatedly (usually 5-10 times) until you see fuel moving through it. This pushes fuel from the tank into the carburetor, making starting easier.
Step 5: Engaging the Decompression Valve (If Equipped)
Older or specific models might have a decompression valve.
- Press: If your saw has a decompression valve, press it. This temporarily reduces compression, making the starter rope easier to pull. It will automatically reseal after the first pull.
Step 6: Pulling the Starter Cord
This is the moment of truth for your Stihl MS170 engine start.
- Pull Smoothly: Grasp the starter handle firmly. Pull the starter cord out steadily until you feel resistance, then give it a few sharp, quick pulls.
- Listen: You should hear a few “pops” or “chuggs” as the engine attempts to fire. This indicates the Stihl MS170 ignition system is working.
Step 7: Adjusting the Choke and Master Control Lever
Once the engine has “popped” or tried to start:
- Disengage Choke: Immediately push the master control lever upwards to disengage the full choke. This will also return the throttle to idle. The engine might continue to run unevenly at this stage.
- Continue Pulling: Give the starter cord another 1-2 gentle pulls. The engine should now start and run.
- Warm Up: Let the engine run for a few seconds to warm up. You can gently blip the throttle if needed.
Step 8: Testing the Throttle
- Engage Throttle: Squeeze the throttle trigger. The engine speed should increase smoothly.
- Release Throttle: Release the throttle. The engine speed should return to a stable idle. If it doesn’t return to idle or stalls, there might be an issue we’ll address in troubleshooting.
Stihl MS170 Cold Start Explained
A Stihl MS170 cold start requires the choke to be fully engaged. The goal is to provide a richer fuel-air mixture to the cold engine. Here’s a recap of the process for a cold engine:
- Ensure the saw is safely positioned.
- Push the master control lever down to engage the choke and fast idle.
- If equipped, press the primer bulb until fuel is visible.
- If equipped, press the decompression valve.
- Pull the starter cord firmly until the engine “pops” or sputters.
- Move the master control lever up (disengaging the choke and returning to idle).
- Pull the starter cord again, gently, until the engine starts.
- Allow the engine to warm up for a few seconds.
Stihl MS170 Warm Start Guidance
When the engine is already warm, the Stihl MS170 warm start is simpler.
- Ensure the saw is safely positioned.
- With a warm engine, you generally do not need the choke. Leave the master control lever in the neutral or run position.
- If the saw is flooded (won’t start after trying to start it warm), you might need to disengage the choke (lever up) and slightly open the throttle while pulling the starter cord. This allows more air into the mix.
- Pull the starter cord. The engine should start directly.
- Let it idle for a moment before using it.
Troubleshooting Stihl MS170 Starting Problems
If your Stihl MS170 isn’t starting, don’t despair. There are common reasons and solutions. Here’s some Stihl MS170 troubleshooting starting tips.
Problem: The Engine Won’t Fire at All
- Fuel Mixture: Is the fuel mix correct? Is it fresh? Old fuel is a common culprit.
- Spark Plug: Check the spark plug. Is it fouled, wet, or damaged? Remove it, clean it if necessary, check the gap, and reinstall. If it looks bad, replace it. The Stihl MS170 ignition relies on a healthy spark plug.
- Ignition System: Is the spark plug wire connected securely? Is there a spark when you pull the cord (test this carefully over a metal part of the engine)? If not, there could be an issue with the ignition coil or module.
- Master Control Lever: Is the lever in the correct position for starting?
Problem: The Engine Tries to Start but Won’t Run
- Choke Adjustment: Did you disengage the choke after the initial “pop”? If not, the engine is likely getting too much fuel.
- Air Filter: Is the air filter clean? A clogged air filter restricts airflow, making the fuel mixture too rich.
- Fuel Filter: Is the fuel filter clogged? This can prevent sufficient fuel from reaching the carburetor.
- Carburetor: The carburetor might be dirty or out of adjustment. This is a more complex issue and might require professional cleaning or adjustment.
Problem: The Engine Starts but Stalls or Runs Poorly
- Fuel Mixture: Again, check your fuel mix.
- Spark Plug: A worn or fouled spark plug can cause irregular running.
- Air Filter: A dirty air filter will cause the engine to run rich and bog down.
- Bar Oil: Ensure you have bar oil. Some saws have a safety feature that prevents the engine from revving high if the oil is too low or the pump isn’t working.
- Chain Brake: Is the chain brake accidentally engaged? This can prevent the engine from revving properly.
Problem: The Engine is Flooded (Smells like Gas, Won’t Fire)
- Flooded Engine: This means too much fuel has entered the combustion chamber.
- Solution: Turn the master control lever to the “stop” position. Move the choke lever to the disengaged (up) position. Open the throttle slightly. Pull the starter cord several times without the choke. This should help clear the excess fuel. Once it tries to fire, follow the normal starting procedure for a warm engine.
Maintenance for Easy Starts
Regular maintenance is key to ensuring your Stihl MS170 starts reliably.
Spark Plug Maintenance
- Regular Checks: Periodically remove, inspect, and clean the spark plug. Check the gap and adjust if needed according to your manual. Replace it annually or if it shows signs of wear or damage. The Stihl MS170 ignition system is sensitive to spark plug condition.
Air Filter Cleaning
- Frequency: Clean the air filter after every few uses, or more often if you’re working in dusty conditions.
- Method: Tap the filter gently to remove loose debris. For a deeper clean, wash it in warm, soapy water, rinse thoroughly, and let it dry completely before reinstalling. Never use gasoline or harsh solvents.
Fuel System Care
- Fuel Filter: Replace the fuel filter annually. It’s a small, inexpensive part that can prevent major starting issues.
- Fuel Stability: If you don’t use the saw for extended periods, use a fuel stabilizer or drain the fuel tank and run the engine until it stops.
Frequently Asked Questions About Stihl MS170 Starting
Here are some common questions about starting the Stihl MS170:
- Q: How do I know if I have the correct Stihl MS170 fuel mixture?
- A: The recommended ratio is 50:1. This means 20ml of Stihl two-stroke oil for every 1 liter of gasoline. Always use high-quality oil and fresh gasoline.
- Q: My Stihl MS170 won’t start. What’s the first thing I should check?
- A: Start with the fuel. Ensure you have the correct fuel mixture and that it’s fresh. Then check the spark plug for a good spark.
- Q: Can I start my Stihl MS170 without oil in the bar oil tank?
- A: The engine will start and run without bar oil, but the chain and bar will not be lubricated. This will cause them to overheat very quickly and lead to damage. Always ensure the bar oil reservoir is full before operating.
- Q: What does it mean if my Stihl MS170 “pops” but doesn’t start?
- A: This indicates that the Stihl MS170 ignition is working and the engine is getting fuel. It usually means you need to adjust the choke or the master control lever correctly after the initial pop to allow the engine to run.
- Q: How often should I clean the air filter on my Stihl MS170?
- A: It’s best to clean it after every few uses, or more frequently if you’re cutting in dusty or dirty conditions.
By following this comprehensive Stihl MS170 starting guide, you’ll be well-equipped to get your chainsaw running smoothly and efficiently. Remember to always prioritize safety and proper maintenance for the best performance and longevity of your Stihl MS170 engine start and operation.