If your chain saw is creating sawdust instead of wood chips, it is time to sharpen the chain.
Step 1: Inspect the chain links for damaged or excessive wear. If damage is detected, it may be time to replace the chain.
Step 2: Select the proper sharpening file and guide. The correct size round file should easily slide into the back curve of the chain’s cutter blade. Typical chains require a 5/32” or 7/32” file.
Step 3: Clean any dirt or debris from the chain and degrease the chain with mineral spirits.
Step 4: Place the saw on a level and sturdy work surface. Mark the top plate of the first cutter blade with a dot from a sharpie marker. This will help you avoid sharpening the same cutter twice.
Step 5: If you have a file guide, use it to position the sharpening file. Twenty percent of the file diameter should be above the top plate of the cutter blade when sharpening the link. Angle the file to duplicate the angle of the cutter blade; typically this is a 25-degree angle.
Step 6: Move the file up from the inside of the cutter blade to the outside. Twist the file slightly as you move it up along the cutter blade. File the blade only on the upstroke and sharpen only the bright angled portion of the blade. Three to five strokes per tooth should be enough to sharpen most links. File each link with the same number of strokes to keep the chain cutter blades equal.
Step 7: Sharpen the cutters on one side of the chain first. Turn the saw around and sharpen the cutters along the other side.
Step 8: Use a flat mill bastard file to lightly file the rakers. Rakers are the front curved hook portion of each link. This will improve the bite of the chain and allow the saw to throw bigger chunks. Typically the raker should be 1/10 of an inch lower than the front tip of the top plate on the link.
Step 9: Once you have sharpened all of the links, adjust the chain tension and reapply bar oil to the chain.