Things You'll Need
The Stihl MS 290 Farm Boss is a chain saw intended for the mid-range user. The MS 290 is designed to take the work out of limbing, felling and cutting larger trees into logs. However, if your chain saw is blunt or damaged, the physical effort needed to work the chain saw is greater. A blunt chain saw also results in greater vibrations, which affects the accuracy of the cutting. To minimize effort and maximize results, it is important to keep your chain saw sharp.
Clean the chain-saw chain and inspect for signs of wear and tear. Put gloves on to protect your hands.
Refer to the "Sharpening Tools (Special Sccessories)" section of the owners' manual (see Resources). Pick sharpening tools -- such as flat file, round file and filing tool -- in line with the chain pitch. The chain pitch is a fraction number that is listed on the side of the cutter. For your chain to be sharpened properly, each cutter must be filed to the same specific angles with the proper file, sharpened to the same length and have depth gauges that are set to the correct height.
Put the round file between the cutting tooth's edge and the depth gauge of a cutter. Hold the file horizontally and at right angles to the side of the guide bar. File according to the angles of the file holder in an inward direction. File with a consistent pressure and number of strokes for the best results. Repeat for each section.
Look for the cutter with the most damage or signs of wear and tear, usually the shortest one. Use this cutter as a "master cutter," or template by which to sharpen the other cutters. Use the flat file to shorten the other cutters to the same length as your master cutter to maximize uniformity and cutting performance.
Place the filing gauge that matches the chain pitch on the cutter. The highest point of the depth gauge and the filing gauge should be the same height. File away the part of the depth gauge that protrudes higher than the filing gauge with a flat file.
Repeat these processes until all of the cutters are uniform again.
Clean the chain once you have finished sharpening. Remove any dust or filings and lubricate the chain.
Shortening cutters with a hand-held file can take a large amount of time. If you have access to a workshop, use an electric grinder to shorten the cutters to the correct length.