Tightening the chain on your Stihl chainsaw is a routine maintenance task essential for safe and effective cutting. The process generally involves adjusting the tensioner screw after loosening the guide bar nuts.
Steps to Tension Your Stihl Chainsaw Chain
Proper chain tension ensures optimal cutting performance and prevents premature wear or damage to your saw and chain. Here's a breakdown of the steps:
- Access the Bar Nuts: Locate the nuts that secure the guide bar to the saw's powerhead. These are typically on the side cover.
- Loosen the Bar Nuts: Using the appropriate wrench (often included with the saw), loosen the bar nuts enough so the guide bar can move freely. You don't need to remove them entirely.
- Locate the Tensioner: The chain tensioner mechanism varies slightly by Stihl model. On models like the Stihl MS-170, the tensioner screw is up in the front, located near the guide bar nose. For other models, it might be on the side cover.
- Adjust the Tension: Turn the tensioner screw clockwise to increase tension (pushing the bar forward) and counter-clockwise to decrease tension (pulling the bar back).
- Check Tension: Lift the nose of the guide bar slightly while adjusting. Turn the tensioner screw until the chain is snug against the underside of the guide bar. A properly tensioned chain should still be able to be pulled around the guide bar by hand, and the drive links should remain in the bar groove without sagging significantly underneath.
- Retighten Bar Nuts: While still holding the nose of the bar up slightly (to maintain tension), tighten the bar nuts securely.
- Final Check: Perform one last check of the chain tension by hand after the nuts are tight.
Important Considerations:
- Always tension the chain when it's cool. Chains expand when hot.
- Too loose a chain can derail, which is dangerous.
- Too tight a chain can cause excessive wear on the bar, chain, and sprocket, and may even damage the crankshaft bearings.
Following these steps, including loosening the bar nuts and adjusting the tensioner screw (located in the front on some models like the MS-170), will help you maintain the correct chain tension on your Stihl chainsaw.
