Chainsaws are not cheap to run, but they get really expensive with neglect and lack of service.  A modern chainsaw is a precision high-tech instrument running at very high revs so it needs special care.  Here are some tips provided by manufacturers, retail agents, and service technicians.

  • Avoid using fuel that has been mixed for a long time.  Put it in the car and mix up some fresh fuel for the saw.
  • If the saw has had unused fuel in it for a while, empty it out and refill it with a fresh mix.
  • Shake the fuel container before you refuel the saw.
  • Use the ratio of oil to petrol recommended by the manufacturer. See Table below.
  • Use good quality oil to mix with the petrol. Get the correct brand of oil from an agent who sells your brand of saw.
  • The air filter acts as the lungs of the engine - clean it regularly.  Make sure you don't damage it when cleaning either in petrol of soap and water.
  • Keep the vents on the saw casing free from dust - use an old toothbrush.
  • Use good quality chain bar oil.  Don't use old car engine oil as its viscosity had been changed.
  • Keep a spare spark plug handy - the correct one for the saw.
  • Don't clean the spark plug with sandpaper as the fine grit particles can get back into the cylinder and do damage.  If it's corroded or damaged, get a new one.
  • Before you loosen the spark plug, blow any dust away from around it before you take it out.  Dust down the cylinder hole can do damage.
  • Keep checking on any nuts and bolts to make sure they are not coming loose with vibration.
  • Keep the chain at the correct tightness - check the instruction book.
  • Keep the chain teeth sharp.  A blunt saw is a dangerous saw as you push it to make it cut.
  • A good place to hold the saw for sharpening is in an engineering vice. Grip the middle of the bar so the chain will go around.
  • Wear a glove on your left hand (if right-handed) to pull the chain around to get to the next teeth.
  • Sharpen the chain teeth at the right angle for what you want to cut. Crosscutting and ripping require different angles. Check in the handbook. A crosscutting angle is mostly used.
  • It's important to make sure a saw cuts evenly and doesn't go offline or grab.  If these problems occur, take them to your local dealer who will show you the correct method of sharpening, or will do it for you.
  • When using a file to sharpen the teeth, remember it only cuts in the forward direction.  Don't scrub it back and forward across each tooth as you only polish the file and blunt it.  Use a wire brush now and again to clean out the metal filings from the file.
  • Make sure you put equal pressure on all the teeth when filing, especially when turning the blade around to do the opposite side.
  • Make sure that the point of the tooth is extremely sharp and that the face of the tooth is very straight and not curved.  It's this point and edge that does the cutting.
  • Keep checking the depth guides on the chain with the correct tool and flat file.  Buy one from your service shop.
  • If you use power-driven chain sharpeners, they make a good quick job but they grind away more teeth metal than a file.
  • Keep checking the splines on the sprocket to see how much wear has taken place.  If they get badly worn, you need a new sprocket.
  • At the end of each day's cutting, take the bar off and clean out all the shavings and dirt, especially any that may block the oil flow.
  • Clean out the groove in the bar and file off any sharp burs that develop on the side of the groove.
  • Turn the bar over now and again to even up any wear.
  • Check the wheel with small sprockets on at the end of the bar to make sure it's running freely.
  • In re-assembling the bar and chain, first, make sure the chain will rotate in the right direction to cut wood.  It goes around clockwise so the cutting edges of each tooth should be facing forwards.
  • Then make sure the chain is at the correct tension.  You should just be able to lift it out of the bar to expose the bottom of the chain.
  • Finally, check that the chain brake works.  Any saw that doesn't have a chain brake is now illegal.

Oil/petrol mixing guide

  1L petrol 4 L 4.5 L 5 L 9 L 10 L
10:1 100 ml 400ml 450ml 500ml 900ml 1000ml
16:1 63 250 280 310 560 625
20:1 50 200 225 250 450 500
24:1 42 170 190 210 375 420
25:1 40 160 180 200 360 400
30:1 33 135 150 170 300 335
32:1 30 125 140 160 280 310
40:1 25 100 110 125 225 250
50:1 20 80 90 100 180 200