Why Is My Chainsaw Not Cutting?

On this page (9 sections)

1. Why is my chainsaw not cutting when the engine runs fine?
2. What does a dull chainsaw chain look like?
3. How do you sharpen a chainsaw chain correctly?
4. Why do depth gauges matter so much?
5. Is my chain too loose, too tight or on backwards?
6. Could the bar or the engine be the problem?
7. When should you stop and replace the saw?
8. What safety gear should you wear while cutting?
9. How do you keep a chain cutting well between sharpenings?

Your chainsaw is not cutting because the cutters are dull, the depth gauges are set too low, or the chain is loose or fitted backwards. Fix the chain first, since a sharp, correctly tensioned chain solves most poor cutting.

Only then look at the engine, the bar and the fuel mix.

Most "why is my chainsaw not cutting" moments come down to a chain problem, not a broken saw. A quick visual check of the teeth and tension takes a minute and points you at the right fix.

Why is my chainsaw not cutting when the engine runs fine?

The engine and the cutting chain work separately, so a strong-running saw can still have a useless chain. If the saw revs up and the chain spins but the bar just skates across the log, the fault is almost always in the cutters or the depth gauges.

Dull teeth scrape instead of slicing. Fine sawdust, a hot bar and the need to push hard all point to dull cutters.

If you see those signs, stop and sharpen rather than forcing the saw through the wood.

A backwards chain is the second common cause. The cutting corners should face forward along the top of the bar, away from the engine.

Fit it the wrong way and the saw spins smoothly but won't bite.

Loose tension is the third. A chain that sags away from the bar slips instead of cutting cleanly.

Check it before every session.

What does a dull chainsaw chain look like?

Dull cutters look rounded and shiny on the cutting edge, and the saw throws dust rather than chips. Healthy wood chips are chunky and roughly the size of a grain of rice.

A dull chain leaves a fine powder that clogs the bar groove.

Hold the saw with the bar pointing away from you and look along the top of the teeth. The cutting corner should be a sharp point.

A rounded corner means it's time to file.

Other signs include a bar that feels hot after a short cut, smoke from the wood and a cut that wanders off your line. Any of these means sharpen before the next tank of fuel.

Keeping the chain maintained also helps it last longer. A quick touch-up every few tanks costs far less than a new chain.

How do you sharpen a chainsaw chain correctly?

Match the file size to the chain pitch and keep the file at the angle marked on the chain. A 3/8-inch pitch chain takes a 7/32-inch round file.

Low-profile 3/8-inch chain takes a smaller file, and your bar or chain markings tell you which.

File each cutter on the same stroke count and angle so both sides match. Alternate left and right cutters and keep the file level with the top plate angle.

Uneven strokes make the saw pull to one side.

Then check the depth gauges. These are the small rakers in front of each cutter, and they set how deep the tooth bites.

A depth gauge tool shows how far to file them down. Too much raker filed away makes the saw grab and kick; too little makes it cut slowly even with sharp teeth.

Which sharpening kit should you buy?

The Husqvarna kit covers the whole job for 3/8-inch pitch chain in one box. It includes a file handle, a combination file guide with a roller guide and depth gauge, two round files and a flat file.

The roller guide holds the correct filing angle, so you don't have to judge it by eye. Buy it if you run 3/8-inch pitch Husqvarna chain and want a simple manual setup.

The Sharp Pebble kit is the cordless alternative. It includes a sharpening tool with an angle guide, a wrench and four sharpening wheels in 5/32, 3/16 and 7/32 inch sizes.

Its adjustable speed settings and angle guide aim to keep every tooth at the same depth. Buy it if you want to sharpen without counting file strokes.

Skip both if your chain is badly damaged or missing teeth. In that case a replacement chain is the faster, safer fix.

Why do depth gauges matter so much?

Depth gauges control how much wood each cutter takes, and the wrong height makes a sharp chain cut poorly. File them too low and the saw grabs and kicks back.

Leave them too high and the cutters can't reach the wood, so the saw skates even when the teeth are sharp.

Most home users file the cutters and forget the rakers. After several sharpenings the rakers sit too high relative to the worn teeth.

The saw feels dull even though you just sharpened it.

Check the gauges every few filings with a depth gauge tool. File them flat and level with the tool's setting.

A combination guide that includes a raker gauge, like the one in the Husqvarna kit, makes this a single step.

If you never touch the rakers and the saw still cuts slowly, this is the first thing to check after the cutter edges.

Is my chain too loose, too tight or on backwards?

Check three things in this order: direction, tension and wear. The teeth should face forward along the top of the bar.

If they don't, take the chain off and refit it.

Tension comes next. With the saw cool, the chain should still lift slightly off the bar when you pull it by hand but snap back.

Too loose and it slips; too tight and it strains the bar and sprocket. Recheck after the first cuts because a new chain stretches.

Wear is the third. A stretched chain that won't stay tight, or one with missing or broken teeth, needs replacing rather than adjusting.

A worn sprocket also wears a new chain quickly.

When is a new chain the right fix?

A new chain is the right answer when the teeth are worn back to the gauge line, several are broken, or the chain keeps loosening. Sharpening a worn-out chain only wastes time.

The Oregon chain is a 16-inch, 3/8-inch low-profile, .050-inch gauge chain with 56 drive links. Oregon designs it with bumper drive links and depth gauges to reduce kickback.

Check your bar length, pitch, gauge and drive link count against your saw's manual before ordering. Buy it if your saw runs that spec and the old chain is past saving.

Skip it if your saw takes a different pitch or gauge. A chain that doesn't match the bar won't cut properly and can be dangerous.

Could the bar or the engine be the problem?

If the chain is sharp and tight and the saw still won't cut, check the bar groove and the engine. A worn or pinched bar groove stops the chain from tracking straight.

Clean the groove and check that the bar rails aren't burred.

On a gas saw, a clogged air filter, old fuel or a wrong mix can cost power. A saw that bogs down in the cut but screams in the air often has a fuel or air problem.

Fresh fuel mixed to the maker's ratio is the first check.

On an electric or battery saw, a low battery or a tripped thermal cutoff cuts power. Let the saw cool and charge the battery fully.

If the chain still stalls, the problem is usually the chain, not the motor.

Bar oil matters too. A dry bar and chain run hot and wear fast.

If the saw is using less oil than usual, see our guide on why is my chainsaw leaking bar oil to check the oil system.

When should you stop and replace the saw?

Stop and replace the saw when a sharp chain and a clean bar still won't cut through soft wood. That usually means a worn clutch, a failing motor or a bent crankshaft.

Repairs often cost more than a new saw at the budget end.

For a gas saw that won't hold power after fresh fuel and a clean filter, a compression check tells you if the engine is worn out. For an electric saw that trips its cutoff constantly, the motor is usually the cause.

If you're buying a replacement for firewood work, our guide to the best chainsaw for firewood covers saws sized for that job. A well-matched saw with a sharp chain saves you the same trouble next season.

What safety gear should you wear while cutting?

Wear a helmet with face and ear protection, plus cut-resistant chaps, whenever you run a saw. A dull chain invites pushing and forcing, which is when kickback is most likely.

Sharpening and cutting both call for the same basic gear.

Our guide to what to look for in a chainsaw helmet explains the face shield and ear protection ratings. For leg protection, compare chainsaw chaps for home use.

Check the chaps' cut-resistance class against the saw you use.

Keep the chain brake working and test it before each session. Never cut with the bar tip buried in the wood, since that's the main kickback trigger.

If the chain keeps slipping or grabbing, stop and fix it before you keep cutting.

How do you keep a chain cutting well between sharpenings?

Sharpen a little and often, keep the chain oiled and check tension before each use. A chain that's touched up regularly never gets badly dull, so you spend less time filing and more time cutting.

Rotate the chain by hand after sharpening to check every cutter. Refill the bar oil each time you fuel up.

Avoid cutting dirty wood or dragging the bar through soil, since grit rounds the teeth fast.

Store the saw with a sharp chain and a clean bar. If you cut a lot of firewood, keep a spare chain on hand so a dull one never stops the job.

Our final answer to "why is my chainsaw not cutting" is simple: check the chain before you blame the engine. Sharpen the cutters, set the depth gauges and tighten the chain, and most saws cut like new again.

Frequently asked questions

How do I know if my chainsaw chain is dull?

Dull cutters throw fine sawdust instead of chips, and the bar gets hot while the saw labors. You'll also find yourself pushing hard to keep the cut going.

A sharp chain pulls itself into the wood with light pressure.

Can a chainsaw chain be put on backwards?

Yes, and it's a common mistake after a chain change. The cutting edges of the teeth should face forward along the top of the bar, away from the engine.

A backwards chain will spin but won't cut.

How often should I sharpen a chainsaw chain?

Sharpen whenever the saw starts throwing dust, cutting slowly or pulling to one side. For occasional home firewood work that often means every few tanks of fuel.

Touching up the cutters before they get badly rounded takes far less time than a full reshape.

Does a loose chain stop a chainsaw from cutting?

It can. A chain that sags off the bar slips instead of biting cleanly.

Check tension before each use and tighten it so the chain still turns freely by hand.

Recheck after the first few cuts because a new chain stretches.