Chainsaws are great tools to have when you need them. Stihl is one of the best companies out there for that kind of equipment. However, over time any piece of equipment can go down or need repair. If your Stihl chainsaw won’t start, we are going to show you how to troubleshoot it, and how to fix it.
The most common reasons a Stihl chainsaw won’t start, is because of a bad spark plug, or a worn carburetor. There could be more complicated problems like fuel intake, and low engine compression. To fix these you will need to replace or rebuild these parts.
We have made this guide to help you troubleshoot problems, and take steps to repair your chainsaw. Learning how to work on small engines, can help you to keep all of your equipment running like a champ.
Table of Contents
- How to Troubleshoot a Stihl Chainsaw
- Common Stihl Chainsaw Problems
- Start with the Sparkplug
- Check the Rewind Spring
- How To Fix a Clogged Carburetor
- Fuel Intake Problems with a Stihl Chainsaw
- Compression Issues
- Related Questions
- How do you start a flooded Stihl chainsaw?
- Do Stihl chainsaws run on a mixture of gasoline and two-cycle oil?
How to Troubleshoot a Stihl Chainsaw
When troubleshooting a piece of equipment such as a chainsaw, you should start with the most simple things first. By eliminating the easy to fix things first, you are more likely to avoid replacing expensive parts, that were never broken in the first place.
This may seem like a no brainer, but first, check to see that there is fuel in the chainsaw. Stihl chainsaws have gasoline and two-cycle oil mixture (make sure the mixture is 50:1.) If there is gas, next think back to when you last put gas in the chainsaw.
If it has been a while, you may need to put new gas in the chainsaw. Old gas can leave a thick residue, and go bad. In this case, you need to remove the gas, clean out the gas tank, and put a new fuel mix into it.
Common Stihl Chainsaw Problems
If your Stihl chainsaw is not starting, there are some common problems that you can look for, to diagnose what the problem is. The fix could be as easy as replacing a bad sparkplug, or drying the sparkplug off because the fuel has flooded it.
- Rewind spring
- Carburetor issues
- Fuel intake
- Low compression
A few of these things you can fix with little or no experience. However, to fix some of these problems, you will need to have experience working on small engines. Don’t be afraid to reach out for help from someone who has more knowledge than you.
I worked at a hardware store for years, and the skills I learned from our small engine repair guy, have come in handy more than once.
Start with the Sparkplug
When troubleshooting, start with the sparkplug. Sparkplugs can go bad and may need to be replaced. You will know if the sparkplug is worn down or bad if the tip is black. You can sand it off and try it again, or replace the sparkplug.
Sparkplugs can also get flooded with gasoline. If you are having problems with the choke, and the chainsaw flooding, take out the sparkplug, dry it off and let the chainsaw sit a while, before putting it back in and trying again.
Sparkplug issues are probably the most common problem with a chainsaw not starting. Luckily it is also the easiest to troubleshoot and to fix.
Check the Rewind Spring
When you pull the starter rope, a rewind spring recoils the rope, using a pulley. If the rewind spring is broken or not engaging, then you will have trouble starting the engine. Everyone has had that moment when you have pulled the starter rope multiple times with no luck.
After a while, the spring can wear out and will need to be replaced. You may also need to replace the starter rope as well. If you are pulling the rope, and the chainsaw is not even trying to start, that is a sign that the rewind spring, or the pulley, is broken.
How To Fix a Clogged Carburetor
When you leave fuel in your chainsaw for too long, the thick residue can clog the carburetor. This is a common problem with any small engine. Check the gas tank first for any thick residue from the old gas, if you find it, chances are the carburetor could be clogged.
The way to fix this is to try carburetor cleaner on the carburetor. In most cases, it will break up the residue, and you will be able to start the chainsaw.
If this does not unclog it, you will have to consider buying a carburetor repair kit. Rebuilding the carburetor with a kit, or replacing the carburetor may be the only option.
If you are not going to be using your chainsaw for a while, then run the chainsaw until the gas runs out. This will ensure that nothing is left in the tank to go bad. Always do this, in the off-seasons, when you will not use the chainsaw.
Fuel Intake Problems with a Stihl Chainsaw
Next, you have problems that can occur with the fuel intake. Fuel intake has many components. To troubleshoot them, you will need to start by checking for bad gasoline. Just like with the carburetor, bad gas can clog fuel lines and filters.
The fuel intake has to have the right mix of fuel and air, check for any restrictions of fuel in the line. Also, check that the air filter is not clogged and that it is getting air. If anything is restricting either of those things, the mix will be off.
Loose fuel hoses and clogged lines are common issues with Stihl chainsaws. This can also cause the carburetor to get dirty, which is another issue. Start with fuel intake issues before you move on to more complex issues, such as compression.
The last, most common problem, is the compression of the engine. This is one of the more complex problems. Compression regulates the fuel and air systems, to keep the engine running. The piston works inside of the cylinder, moving up and down, creating compression.
If the compression is not being regulated as it should be, the piston will seize up in the cylinder, destroying the motor. To keep this from happening, you need to make sure that there are no clogged fuel lines, or any air escaping the lines.
If there is a leak in the lines, the compression will be low, and the chainsaw will not be able to keep running. Find the problem and fix it, before it causes the pistons to seize. If it is left unchecked or fixed, you may have to buy a new chainsaw.
How do you start a flooded Stihl chainsaw?
To start a flooded chainsaw, remove the spark plug, clean the fuel off, and let it dry. Let the chainsaw sit for around ten minutes, before putting the sparkplug back in, and trying again. If this does not work, use the methods in this article to troubleshoot the next issues.
Do Stihl chainsaws run on a mixture of gasoline and two-cycle oil?
Yes, these chainsaws use a mixture of 50:1 with gasoline and two-cycle oil. Using the right mixture is the most important part of keeping your chainsaw running and in good shape. Using only gasoline is not safe for these engines and will damage your chainsaw.