How to Fix a Chain Saw Chain

Chain Doesn't Cut

1). Shut off the saw. Disengage the chain brake by pulling back on the black lever on top of the chain saw. Make sure the chain isn't on backward; even professionals sometimes make this mistake. Examine the cutting teeth -- they will be angled toward the wood and away from the sawyer (the person cutting the wood) when the chain is properly attached.
2). Sharpen all the teeth with the round file. Put on leather gloves. Push the round file across the entire length of the tooth at a 60-degree angle with the saw's engine. Keep the round file perpendicular at all times when pushing it across the tooth. Sharpen all the teeth on both sides of the chain in the same way.
3). Place the raker gauge on top of the raker, which is the stubby, flat metal part directly in front of every tooth. Make sure the raker isn't sticking above the raker gauge. Flat-file the raker with smooth, flat, perpendicular strokes, until it is level with the gauge. Do not overfile the raker -- this can put the sawyer in danger.

1). Turn off the saw and disengage the chain brake. Loosen the bar nuts with the wrench. Unscrew the bar tensioner screw with the screwdriver. Remove the bar cover, bar and chain. Separate the chain from the bar.
2). Check the entire inner ring of the chain to make sure that none of the guide links or rivets is bent or damaged. Replace the chain if any of these is broken.
3). Clean the guide slots on the guide bar with the knife. Insert the tip of the knife into the slot near the tip. Scrape out all the compacted sawdust and oil, which can stop a chain from spinning. Clean out the bar's two lubricating holes near the end of the bar, using the knife.
4). Spin the sprocket tip on the nose of the guide bar. Make sure the tip isn't bent, crooked or damaged in any way. Replace the guide bar with a new one if its tip won't spin, or is warped or bent.
5). Set the chain back on the bar. Set the bar and chain in place. Tighten down the bar cover's bolts until they are finger-tight. Tighten the bar tensioner screw with the screwdriver. Turn the screw clockwise until proper chain tension is achieved. Pull down on the chain with a gloved hand to check for proper tension. It shouldn't be too tight or too loose.
6). Try spinning the chain with a gloved hand. If the chain still doesn't work, the chain saw's drive system probably needs some repairs.