Generally I don't problem with Stihl fuel lines but it does happen. As a general rule here these fuel lines are always check during carburetor rebuilds. And mentioning carburetor rebuild with Stihl now owning a controlling interest in Zama most of those rebuild kit are none existence now as My dealers can't even get them when I provide them with the Stihl part numbers; just complete carbs. I threw out about 30 carbs last year that were rebuild-able due to lack of the repair kits. A shame to have to do it. Now the Walbro carbs are still repairable as Stihl has gotten to them yet.
Now when it come to Stihl dealer do your research some are reasonable and other are ridiculously priced on parts. I got one here that is nearly doubled on prices compared to the one I used now.
But I would not carry anything else in for warranty due to them not a well trained Stihl techs. Supposed to go thru Stihl certification but the one I got recently couldn't even find a bad spark plug. I had to.