Chainsaw cuts crooked or smokes: inspect the complete cutting system

Why does my chainsaw cut in a curve?

Because the cutters on one side are removing less wood than the other, so the saw steers toward the side that cuts less. Usually one side hit dirt or a nail and was filed back harder, leaving it shorter. File every cutter back to the length of the shortest one, and also check the depth gauges are even and the bar rails are not worn, because a leaning chain on a worn bar produces the same curve.

Why does my chainsaw make fine dust instead of chips?

Because the chain is dull, or the depth gauges are too high so the cutters cannot reach the wood, and after three or four sharpenings the gauges are almost always the missed step. A sharp, correctly gauged chain throws coarse chips the size of rice grains and does not need you to lean on it; fine dust with pressure means sharpen, then lower the depth gauges with a tool rather than by eye.

Why is my chainsaw bar smoking and getting hot?

Because the chain is running dry. The oiler is not delivering, or the oil is too thick for the temperature. Stop cutting and check the oil tank, the outlet hole in the bar mounting face, and the bar groove, all of which pack with sawdust.

A bar run dry develops permanent blue heat marks and burred rails; the everyday check is that the bar-oil tank should empty at roughly the same rate as the fuel tank.

How do I check my chainsaw oiler is working?

Hold the running saw with the bar nose a hand’s width from a light-colored surface and briefly open the throttle; a visible line of oil should be flung onto it. No line means stop cutting and find out why before the bar overheats. The everyday version of the same check is that if you finish a tank of fuel with bar oil left over, the oiler is not delivering as it should.

Why does filing every cutter to the length of the shortest one fix a chain cutting crooked?

Because uneven cutter length means one side of the chain removes less wood per pass than the other, and the saw steers toward the side cutting less: filing all cutters down to match the shortest one restores equal removal on both sides, which is what makes the saw cut straight again, even though it sacrifices some cutter length in the process.

What are depth gauges on a chainsaw chain, and why do they need lowering after repeated sharpenings?

Depth gauges are the raised tabs in front of each cutter that limit how deep the cutter can bite into the wood on each pass. As cutters are repeatedly filed back during sharpening, they get shorter while the depth gauges stay the same height, eventually limiting the cutter's bite so much that the chain produces fine dust instead of chips even though the cutters themselves are sharp.

Can a worn drive sprocket cause a chainsaw to cut crooked?

A worn sprocket more commonly causes chain slack, jumping, or accelerated chain wear rather than crooked cutting specifically: uneven cutter length or a worn bar rail are the more likely causes of a curving cut, but a badly worn sprocket is worth inspecting as part of a broader chain-and-bar health check if the crooked-cutting fix doesn't fully resolve the symptom.

Does bar oil viscosity need to change with the season, the way engine oil sometimes does?

Yes for extreme temperature ranges: a bar oil too thick for cold weather flows poorly and can starve the bar despite a functioning oiler, while summer-weight oil in very cold conditions may not reach the bar tip efficiently. Some manufacturers offer a winter-weight bar oil specifically for this reason; check the oil's own temperature rating rather than assuming one weight works year-round in a cold climate.

What does it mean if only part of the bar rail shows wear, rather than the whole length?

Localized rail wear typically indicates the chain sits unevenly in the groove at that specific point, often from a chain that's been run too loose (allowing it to bounce in the groove) or from repeated cutting concentrated at one section of the bar: inspecting for a groove width that's widened specifically at the worn section helps confirm this before replacing the whole bar.

Is it normal for a chainsaw to produce some smoke when cutting dense, dry hardwood even with a well-oiled chain?

A small amount of friction-generated warmth is normal in dense wood, but genuine visible smoke from the bar or chain is not. It specifically indicates the chain is running hotter than the bar oil can manage, whether from insufficient oil delivery, a dull chain generating excess friction, or both, and should be treated as the oiler-check symptom the guide describes rather than dismissed as normal for hard wood.

Why does a chain need to be re-tensioned periodically, and does loose tension affect cutting quality?

A chain stretches slightly with normal use and heat cycling, and a chain that's too loose can derail from the bar or cut erratically as it bounces rather than tracking smoothly in the groove: checking and adjusting tension is routine maintenance distinct from sharpening, and a loose chain can produce cutting-quality symptoms that look similar to a dull or unevenly filed chain.

Should I suspect the chain or the bar first if a saw both cuts crooked and smokes at the same time?

Check the oiler and bar condition first, since smoking indicates an active thermal problem that can itself distort cutting behavior. A bar running hot from oil starvation can also produce erratic, crooked-feeling cuts as the chain binds slightly in an overheating groove, so resolving the smoking symptom may also resolve what initially looked like a separate crooked-cutting fault.