Chainsaw Not Cutting It? Top 4 Reasons Why

Home » Chainsaw Not Cutting It? Top 4 Reasons Why

Whether it’s being used to trim tree branches, remove trees altogether, or to harvest firewood, a chainsaw is the kind of hand-held outdoor power equipment that sees a lot of action during the autumn months. If you find your chainsaw is not cutting like it used to, you can probably improve its performance with some simple maintenance or part replacement.

Before you can confidently troubleshoot why the chainsaw isn’t cutting it, you should first have a good grasp on how a chainsaw does what it does…

How a chainsaw does its cutting

The crankshaft of the chainsaw’s gas-powered engine extends out the side of the crankcase and connects to a centrifugal clutch. At idle speed, the engine will run but not fast enough to engage the chain. When the throttle trigger is pressed, the engine accelerates, causing the clutch flyweights to extend outward and begin to rotate a drive gear attached to the chain.

The chain rides in a track on a bar. As the clutch rotates, it also operates a pump to supply chain oil to the bar. This specially-formulated chain oil is thick and designed to stick to the bar and chain, so be aware that standard engine oil should never be used as a substitute. The oiler hole (where the chain oil excretes from) should always be kept clear of debris to ensure proper lubrication; otherwise, the bar, chain, or engine could become damaged.

For safety purposes, many chainsaws incorporate a chain brake that can be activated manually or automatically to stop the chain if you encounter any kickback during operation. The brake should also be engaged when moving short distances to help prevent injury. Some chainsaws are equipped with a chain guard to keep the tip of the saw from coming into contact with an object or person. Although this safety feature can make the chainsaw less versatile, it is recommended for inexperienced users.

Top 4 reasons why a chainsaw isn’t cutting

So, without further ado, here are the four most probable causes of your chainsaw failing to cut:

  1. Worn cutting chain  –  This one may seem obvious, but there are a couple of options to consider, and good practices to follow to correct the problem. First, you will need to evaluate just how worn the chain is. You may be able to get more life out of the existing chain by sharpening it. You can use a rounded file to sharpen the side and top plates of the cutting teeth and a flat file to sharpen the depth gauge to maintain its shape, but a standard rattail file is not recommended as it can damage the teeth. Another option will be to use a dedicated chain sharpening tool to handle this. If you’ve already attempted to sharpen the chain multiple times before, it’s probably time to replace the chain with a new one. Keep in mind, when installing a new chain, the teeth of the chain should face away from the engine on the top of the chain bar and towards the engine on the bottom of the bar. After you replace the chain, be sure to follow the manufacturer’s recommendations for the proper tension setting. This leads to the second most likely reason the chainsaw won’t cut…
  2. Improperly adjusted chain  – Even a new chain, if not properly adjusted, can fail to cut adequately. If the chain is too loose, it may not be able to make good contact with the wood, or the drive gear may not engage properly. A loose chain could also become dislodged from the bar and cause injury. If the chain is too tight, it will not rotate freely, reducing its cutting potential. In addition, a “too tight” chain can also damage the engine or clutch. You can rotate the chainsaw’s adjustment screw or knob to tighten or loosen the chain as necessary, but always follow the manufacturer’s guidance for the proper tension setting for optimal results.
  3. Damaged chain bar – If the chain bar is bent or worn out, the chain won’t be able to rotate properly. You can replace the damaged bar with a new one but remember to keep the oiler hole in the bar clear of debris to maintain proper lubrication. Otherwise, the chainsaw can suffer continual damage.
  4. Worn clutch – The clutch pads engage the clutch drum to rotate the chain. If the pads or drum are worn out, the chain will have trouble cutting. You can replace the clutch drum or the entire clutch assembly with new components to solve the problem.

Bonus troubleshoot tips

As mentioned earlier, many chainsaws will have a chain brake or chain guard installed. Potentially, a damaged brake or bent guard could be interfering with the rotation of the chain. If you have either of these two components on your chainsaw, you should confirm they are in good condition and operating as intended.

This is also true of other chainsaw parts. A defective throttle trigger or cable could also affect the ability of the clutch to drive the gear that drives the chain, so it’s always a good idea to inspect all equipment parts if the chainsaw if not operating as expected.

Repair Clinic has the right chainsaw parts for your model

Where can you find a replacement chain for your chainsaw? The same place you can find the right chain bar, chain tensioner, clutch assembly, throttle trigger, carburetor, or fuel filter: Repair Just enter the chainsaw’s full model number in the Repair Clinic website search bar to see a complete list of compatible parts. You can then use the “Part Category” filter (Example: “Chain & Bar”) followed by the “Part Title” filter (Examples: “Chain” or “Chain Tensioner”) to find the specific part you need. In addition to stocking original manufacturer parts from such top chainsaw brands as Craftsman, Echo, Homelite, Husqvarna, MTD, Poulan Pro, Ryobi, Stihl, and Tanaka, Repair Clinic also has hours of “how-to” video content covering chainsaws. Enter your equipment’s model number in the “Repair Help” section of the website to view all related video help, plus relevant schematics, and diagrams.

Repair Clinic VIP Email

Join the Repair Clinic VIP email list for updates and special offers!

Scroll to Top