Chain loosening on echo 330t

[Canadiana]

I have a new stihl chain on this saw. It has not been used much. Stays sharp a long time and continues to get surprisingly loose after 10-15 mins use. Chain has been touched up 3 or 4 times. Some stretching is expected. Chain is expected to stretch with heat. I do not like a tight chain. On this 14" bar the entire drive link (just one) should be visible when i give the chain a good pull down or up. The bar nuts have never come loose on their own. The oregon chain that came before the stihl replacement also did the same thing and it was used until i thought the cutters would break off. Let me know of similar issues, solutions, or causes. Thanks

[sawguy21]

Is it getting enough oil?

[Canadiana]

Yes, more than needed. When wot it sprays a bit at the end. The saw goes through oil nearly as fast as mix and drips oil after its been run awhile

[dougand3]

1. Chain stretches? Unlikely if used multiple times
2. Chain tensioner pin loosens? Shouldn't happen if bar nuts are tight
3. Sprocket has wear? You're tightening chain on a ridge and then drivers slip into a valley.

[mike_belben]

Debur the bar rail grooves with a file or on a belt sander with 90* rest.  Watch out for the sprocket tip.

Grind the but of your favorite file to make a groove cleaner, scrape the shmeg out.  Brakekleen the groove and blow it out, clear the oil holes. 

Check the condition of your drive teeth in the crank.  Be certain the pitch matches your sprocket tip and chain pitch.  Make sure your bar and chain are the same guage.

Tighten the chain tighter than you normally do so it snaps back like a bungee cord.  Hold it WOT against cardboard.  Verify a good oil fling.  Lift chain to verify oil on the rails. 

Stay out of the dirt and especially out of doaty rotted centers.  Nothing gets my bar smoking hot or stretches the heck out of my chain like a summer hickory or white oak with a big dirty rotten ant chimney up the center.  That composted tree dirt goes right into the works and dulls then burn up a chain im an instant.

If you arent in dirty hearted wood like described, drop the chain off for a machine sharpening and see if it still does it.  Over time my hand file drifts and i start cutting scallopped potato chips.

[mike_belben]

If your chain is ever sparking our coming out of the bar groove or getting grabbed by the kerf its too loose and/or too dull.  Rakers need to come down more and more as the cutters get shorter to maintain the correct tip up in the cut.   

You got the right sized file and you arent letting it climb farther and farther out of the gullet as you sharpen back?  Should only have 20% of the file round up above the cutter tooth.  Every so often i have to file a few strokes straight down on the link to lower the gullet floor, them push back against the cutter tooth.