Stihl PM3 is 1/4 pitch .043 gauge. As far as I know the only sprocket nose bars that work are Panther. Stihl bars can be modified to fit on the 2511, and the .043 carving bars work, but the Panther is better imho. The performance of carving bars isn't ideal for general tree work. The Stihl bars...
I'm a fan of the 12" bars for weight balance on the 2511. The solid carving bars are nose heavy, but the laminates feel good.
For a faster cutting setup if you have the power: Sugihara light type pro with Oregon 95txl is a good combo if the budget allows. Woodland Pro has a good budget bar and...
Not trying to resurrect an old thread, but I have been running a good 1/4" bar for a couple of weeks. Check out the Panther mini bars. They mount up properly to the Echo, and work well with Stihl PM3 chain. They are great for pruning with the taper, and cut smooth with a stock or mod saw.
If the caps don't loosen easily, they were put on too tight. All chainsaws had basic caps like these for 60 years until the Stihl flippy caps. I'm a fan of the Husky flippy myself. The starter handle only comes out after my groundy over tightens the caps.
I've been running the Echo 2511 for over a year now. Great little saw, but imo comes with cheap junk for a cutting system in the USA. We get the option of a 12" or 14" bar with jumpy 3/8 lopro. The easiest fix to get a smooth cut is to run a narrow kerf setup with 3/8 .043. Another option is...