my husqvarna 455 rancher chain keeps coming loose and slipping off the bar while i'm cutting. am i doing something wrong?

This usually means the chain tension isn't set correctly or the bar is worn. Here's how to fix it properly.

1. First, stop the engine and make sure it's cool. Engage the chain brake for safety.
2. Loosen the bar nuts just enough so you can adjust the tensioning screw.
3. Lift the tip of the bar up and turn the tensioning screw clockwise until the chain is snug against the bar's underside. You should be able to pull the chain around the bar by hand with slight resistance.
4. While holding the bar tip up, retighten the bar nuts firmly.

IF THAT DIDN'T WORK: The drive sprocket or the bar itself could be worn out, preventing proper chain seating. Check the bar's guide groove for excessive wear and the sprocket for damaged teeth. A worn chain can also stretch unevenly and not hold tension.

HEADS UP: Always re-check chain tension after the first few minutes of a new cutting session, as a new chain will stretch. A loose chain is a safety hazard.