Hi. So I bought a new MS 171 a few weeks ago and since then only had a chance to cut a small limb until today. While cutting, I felt that the chain was a bit tight, so I went to loosen the chain a tiny bit. While I went to undo the bar nut, it felt a bit tough to undo, but felt it was coming. Well, to my disbelief, as I was undoing it, the bar came off with the side cover still attached. The bar mounting stud that normally stays in the engine side came out. I carefully grabbed it good with pliers and removed the nut as is supposed to happen. I then carefully screwed the bar mounting stud back into the engine using the bar nut and a wrench. I put the saw back together as normal and it worked fine. The main question is how tight is the bar nut supposed to be? This is the first time it had been taken off since it was assembled at the store where purchased. Is this a big problem where I should take it back, or does anyone think it will now be alright. Today when I tightened it, I just snugged it up well, but did not reef on it. Thank you.