Small Engine Repair: Chainsaws

This section of the website will explain about chain saws and the weird things they can do while cutting.

Don't automatically assume the bar is bent! Nine times out of ten, the teeth on the chain is at fault. You hit a rock or a bullet or something harder than the tooth, knocking it back, causing the tooth to be rounded and a little shorter than the opposite tooth. Saws tend to pull to the side of larger teeth, because they are the fist to bite into the wood.
Chain was not sharpened evenly. The teeth are not cut back to the same length on both sides, causing the saw to pull to the side of larger teeth.

Sharpening a chain is just half of the job. The depth guages, or "drags" must be cut also. When a chain is sharpened, some of the tooth is removed, and makes the tooth lower than the drag. When the drag is above the tooth, it limits how far down the tooth can bite into the wood, thus poor cutting. The more powerful the saw, the more of the drag you can take off. See your saw's instructions for more information.

Chain is not being lubricated. Caused by a stopped up bar, plugged oil line, or damaged oil pump. The chain is getting hot and stretching, causing it to jump off the bar.
Chain too loose. On sprocket nose bars, the chain needs to be tighter on the bar than hard nose bars. A chain is tight on the bar, when you pull up on the chain and the bottom of the driver just be visible.

Stay out of the dirt! Dirt is the number one enemy of anything sharp and fast moving. Unlike large solid objects like rocks and nails, which hit only a few teeth before you know you have hit something, dirt hits all of the teeth, and makes them dull before you even know what happened. Also, hardwoods, such as locust and oak are hard on chains.

Small Engine Repair