Hey everyone, have you ever been knee-deep in a DIY project only to have your trusty Stihl MS 251 chainsaw suddenly act up? It’s one of those moments that can really throw a wrench in your plans, right? Well, you’re not alone. Whether you’re a seasoned pro or a weekend warrior, understanding the common issues with this popular chainsaw and knowing how to troubleshoot them can save you a lot of frustration and time. Let’s dive into some of the typical problems you might face with the Stihl MS 251 and how to get your chainsaw back to working order.
Common Issues with Stihl MS 251
1. Starting Problems
One of the most frequent issues users encounter is difficulty starting the chainsaw. This can be incredibly frustrating, especially when you have a big project waiting. Here are some reasons why your chainsaw might not be starting:
- Old or Bad Fuel: Over time, fuel can degrade and cause starting issues. Always use fresh fuel and consider using a fuel stabilizer if you plan on storing your chainsaw for an extended period.
- Clogged Carburetor: The carburetor might get clogged with debris or old fuel. Cleaning or rebuilding the carburetor can often solve this problem.
- Spark Plug Issues: A dirty or damaged spark plug can prevent the chainsaw from starting. Check and clean the spark plug or replace it if necessary.
2. Chainsaw Stops Mid-Operation
Imagine you’re in the middle of cutting, and suddenly, the chainsaw dies. This abrupt halt can be due to several reasons:
- Fuel Issues: Again, old or contaminated fuel can cause the engine to stop. Ensure you’re using clean, fresh fuel.
- Overheating: Continuous use without breaks can cause the chainsaw to overheat. Give your chainsaw some rest to cool down.
- Air Filter Problems: A dirty air filter restricts airflow to the engine, leading to a shutdown. Regularly clean or replace the air filter.
3. Chain Issues
A chainsaw is only as good as its chain. If the chain is dull or loose, it can affect the performance and safety of your saw:
- Dull Chain: A dull chain makes cutting difficult and dangerous. Sharpen the chain regularly or replace it when necessary.
- Loose Chain: A chain that’s too loose can derail, which is hazardous. Always ensure the chain tension is correct before using the saw.
4. Oil Problems
The bar and chain require constant lubrication to function correctly. Oil problems can lead to significant damage:
- Oil Pump Failure: If the oil pump isn’t working, the chain and bar won’t get the necessary lubrication. Check the oil pump for functionality.
- Blocked Oil Passage: Sometimes, the passage can get blocked, preventing oil from reaching the chain. Clean the passage to ensure proper oil flow.
5. Vibration Issues
Excessive vibration can make using the chainsaw uncomfortable and even dangerous:
- Loose Parts: Vibration can loosen screws and bolts. Regularly check and tighten any loose parts.
- Damaged Anti-Vibration System: The anti-vibration system might be worn out. Inspect and replace if needed to reduce vibration.
Troubleshooting Tips
Starting Problems
If your chainsaw won’t start, try these steps:
- Check the Fuel: Ensure you’re using fresh fuel and the correct oil mixture.
- Inspect the Spark Plug: Clean or replace the spark plug.
- Clean the Carburetor: Remove any debris and check for blockages.
Chainsaw Stops Mid-Operation
To address this issue:
- Cool Down: Allow the chainsaw to cool if it’s overheating.
- Fuel Check: Ensure the fuel is clean and fresh.
- Air Filter: Clean or replace the air filter regularly.
Chain Maintenance
For chain-related issues:
- Sharpen the Chain: Use a sharpening tool to keep the chain sharp.
- Adjust Chain Tension: Ensure the chain is properly tensioned.
Oil System Maintenance
If you’re having oil problems:
- Check the Oil Pump: Make sure the oil pump is working.
- Clean Oil Passages: Remove any blockages in the oil passages.
Reducing Vibration
To minimize vibration:
- Tighten Loose Parts: Regularly check and tighten screws and bolts.
- Inspect Anti-Vibration System: Replace any worn-out parts.
Preventative Maintenance Tips
To keep your Stihl MS 251 in top condition, regular maintenance is key:
- Regular Cleaning: After each use, clean the chainsaw to remove debris.
- Check the Chain: Regularly inspect the chain for sharpness and tension.
- Fuel System: Use fresh fuel and clean the fuel system periodically.
- Air Filter: Clean or replace the air filter as needed.
- Regular Inspections: Periodically check the entire chainsaw for any signs of wear or damage.
Top 10 Most Searched Questions About Stihl MS 251 and Their Answers
1. Why won’t my Stihl MS 251 start?
There could be several reasons your Stihl MS 251 isn’t starting, including old or bad fuel, a clogged carburetor, or a dirty spark plug. Start by checking the fuel and spark plug, and clean or replace them if necessary. If the issue persists, inspect the carburetor for clogs.
2. How do I adjust the chain tension on my Stihl MS 251?
To adjust the chain tension, first, loosen the nuts on the side panel. Then, use the tensioning screw to adjust the chain’s tightness. The chain should be snug against the bar but still move freely when pulled by hand. Finally, tighten the nuts back up.
3. What type of fuel should I use for my Stihl MS 251?
Use a high-quality unleaded gasoline with a minimum octane rating of 89, mixed with Stihl 2-cycle engine oil at a ratio of 50:1 (one gallon of gasoline to 2.6 ounces of oil).
4. How often should I sharpen the chain on my Stihl MS 251?
Sharpen the chain whenever you notice a decrease in cutting performance, such as if the chain pulls to one side or requires extra effort to cut. On average, this might be after every 5-10 hours of use.
5. Why does my Stihl MS 251 chainsaw keep stopping?
The chainsaw might stop due to old fuel, a dirty air filter, or overheating. Check and replace the fuel, clean the air filter, and allow the chainsaw to cool down periodically during use.
6. How do I clean the air filter on my Stihl MS 251?
To clean the air filter, remove the filter cover and take out the air filter. Wash it with warm, soapy water, rinse it thoroughly, and let it dry completely before reinstalling it.
7. What should I do if the oil isn’t reaching the chain on my Stihl MS 251?
If oil isn’t reaching the chain, check the oil pump for functionality and clean the oil passages to remove any blockages. Ensure the oil tank is filled with the correct type of bar and chain oil.
8. How can I reduce the vibration on my Stihl MS 251?
Reduce vibration by regularly checking and tightening any loose screws and bolts. Inspect the anti-vibration system for any worn-out parts and replace them as needed.
9. How often should I perform maintenance on my Stihl MS 251?
Regular maintenance should be performed after every use. This includes cleaning the chainsaw, checking the chain tension and sharpness, inspecting the fuel system, and cleaning or replacing the air filter. Periodic inspections for wear and tear are also recommended.
10. What are the most common replacement parts for the Stihl MS 251?
Common replacement parts include the spark plug, air filter, chain, bar, and oil pump. Regularly inspect these parts and replace them as needed to ensure optimal performance and longevity of your chainsaw.
By keeping up with these maintenance tips and troubleshooting common issues, you can ensure that your Stihl MS 251 chainsaw remains a reliable tool for all your cutting needs. Happy sawing!