It should be snug against the bar, but still pull freely by hand. Let me explain the right way to check and adjust it.
First, always adjust the chain tension with the saw cold. A hot chain expands and will be too tight if you set it warm. Here's the process:
- Loosen the two nuts on the side cover (the bar nuts). Just crack them loose—don't remove them.
- Lift the tip of the bar up to take slack out of the chain.
- Turn the tensioning screw (located near the front of the saw, just ahead of the bar) clockwise until the chain is snug against the underside of the bar.
- Now, check the tension. You should be able to pull the chain away from the bar, midway between the tip and the saw body, just enough to see the bottom of the drive link. The drive link should not come completely out of the bar groove.
- While holding the bar tip up, tighten the two bar nuts securely, alternating between them.
If you're constantly adjusting, the chain is stretching because it's new—that's normal for the first few tanks of fuel. If an older chain keeps loosening, it's worn out and needs replacement. Also, a dull chain creates more friction and heat, causing more expansion and slack.
A final tip: Always check chain tension before each use, and re-tighten as needed with the saw cold.