Chain-saw maintenance

How to keep your saw cutting

With fall yard cleanup work approaching, you'll be happy to know that today's chain saws (Ratings are available to subscribers) are better and safer than ever. But if you don't properly maintain your saw, you might need to replace it or pay a pro to repair it.

The simple steps we've included here will keep most any chain saw running reliably for years. Note that most of the tips here are for plug-in electric saws. The engine-maintenance tips apply only to gasoline-powered saws.

For a saw that's sat for more than a season

• Inspect the entire saw for loose parts, cracks, and other problems.
• Make sure the chain brake (the guard bar just in front of the top handle) stops the chain as soon as you push it forward. If it doesn't, get it repaired by a dealer.
• Check the chain bar for bent rails and replace it if necessary. Also replace the bar if it is worn. You'll know it's time replace the chain bar if the sides of the bar are starting to mushroom out; also check that the depth of the groove that supports the chain conforms with the owner's manual. Chain bars typically are available at large retailers and dealers for about $25 to $50, including the chain.
• Use a stiff brush or compressed air to clean the cooling fins on the flywheel, the cylinder fins, the area outside the carburetor, and the starter housing.
• Replace or clean the air filter (check your owner's manual); some filters can be washed and reused. You'll know it's time to buy a new filter or clean the current one when the saw is down on power. Also change the spark plug after roughly 100 hours of running, and replace the fuel filter at least once each season.
• Before each use, be sure the chain is properly tensioned. The chain should be snug against the bottom of the bar but not so tight that you can't move it around the bar by hand (wear gloves).
• Check that the chain-oil reservoir is full. If it's not, fill with the appropriate oil.
• Refuel the saw using the proper ratio of gasoline and oil (check the owner's manual). Too much oil will cause poor running, increased exhaust emissions, and fouled spark plugs; too little can damage or destroy the engine. Also be sure you shake the gas and oil mixture before you add it to the saw's tank, since oil tends to settle to the bottom.

During regular use

• Retension the chain each time before you use it.
• Sharpen the chain if it's dull (you'll know it's time when cutting takes longer and the wood dust is fine rather than course chunks). Consider having the job done by a pro (about $7 to $10). Also keep an extra, sharpened chain handy (chains cost about $15 to $25) so you can quickly put on a sharp one and keep on sawing.
• Check that the chain doesn't run when the engine is idling. If it does, lower the engine idle speed as suggested in the owner's manual. This step is important-a chain that runs at idle speed is a safety hazard.
• Periodically rotate the bar for even wear by flipping it so the bottom edge is on top.
• Make sure the throttle trigger works smoothly. Also check the chain brake.
• If the saw will sit for more than a week or so, return any unused fuel to its container.