You can tell a chainsaw is dull by the sound it makes. There’s no clean snarl of a sharp bar chewing through wood. No, you hear a high-pitched whine that vibrates in your teeth while sawdust seems less like chips and more like fine powder.
Pushing harder only result in a bogged down engine and dragging chain. It’s fighting with you, so much so that it feels like its the machine doing the work instead of you. This create heat and increases wear on all component.
How To Sharpen A Stihl Chainsaw
Signs Your Chainsaw Is Dull
If ignored, what should of been a ten minute job becomes an hour long struggle. Chainsaw sharpening isn’t about brute force. It’s about geometry.
Getting those cutter teeth to the right angle again make them bite cleanly through fiber. The fear among most owner is that they’ll break their chain in the process, but following a logical sequence it’s very forgiving. It takes a steady hand and patience, but the payoff are immediate.
A sharp chain run cooler, use less fuel, puts far less stress on its sprockets and engine, and cut faster. It’s the single best piece of maintenance you can do for your saw. First thing’s first: Secure the saw before touching the file.
Safety and Preparation Steps
Set it down on a flat, steady surface. Open the side cover and push the chain out of the way to expose cutters. If possible, secure the bar with the chain brake locked into position.
Otherwise, hold it with a clamp. Don’t file when the chain might slip and cause an injury as well as an uneven cut. Make sure tool is secured before proceeding.
It sounds simple, but hurrying this process will come back to bite you. Choose the right round file for your Stihl chain, the size varies with both the cutter’s gauge and pitch. They are commonly available in sizes 4.0mm, 4.8mm or 5.0mm.
Choosing the Right File Size
This size will be stamped into drive links. File that is too big will round the corners of the tooth; too small and you’ll make flat spots. You want the cutting edge to look like it did originally, so follow a guide on the file to ensure uniform depth.
Filing Technique and Angles
Pull the file away from you and apply pressure only on the pull stroke. Don’t touch depth gauge behind it. Use the right angle.
It is typically 30 or 35 degrees for a Stihl chain; check it against your particular model’s file. Many Stihl chains comes pre-marked with colored lines and a built-in file guide showing you the angle. Line up your file with the mark on the tip of the cutters.
Pulling toward yourself, work from inside to outside of the tooth. Only apply pressure on the pulling stroke, allow the file to go limp on the back stroke. Do this three or four times on each tooth, counting consistently.
File three strokes on one, three on another, etc. Also, when you’re done sharpening those cutters, take a look at your depth gauges or rakers. They don’t get shorter when you file teeth down. Initially, they’ll remain their full length, but the cutters will be shorter due to filing.
Filing Depth Gauges and Rakers
So the rakers may stick out too far, which chokes the chain and keeps the cutter from digging in deep enough. Check their height with a gauge tool and file off any too-high raker. People forget this one, and that’s why you have a newly filed chain that still doesn’t seem very sharp.
Final Maintenance and Tensioning
Get the rakers back down to new cutter profile. Then oil the chain well and remove any metal filings from the chain links as well as the bar groove with a good stiff brush or one made specifically for this use. Re-oil the bar and chain with new oil, tension the chain so it snaps back when pulled away from the bar but still turns by hand, and you are ready to rock and roll.
Reassemble and tension the chain on the bar, it should snap back when pulled away from the bar but still be able to turn by hand. Check by running it a short time just hanging in the air to see if there is any binding. With a sharp Stihl chainsaw, cutting goes from being a chore to a quick job.
The cut is clean and engine breathes better. Then you can get back to enjoying what you were doing instead of wrestling with the tool.