MS 171 Bar Tightening Issue

[lil171]

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.

 

[HarleyT]

Take it back and tell them that it was overtightened or crossthreaded by the dealer before you bought it.

 

[homemade]

Definitely in the “snug” range. But not all the way to “reef” on it. If you have to grunt when removing the bar nuts with a scrench, they are too tight.

 

[lil171]

Just an update. I called my dealer today and talked to them of my problem. I said I would go see them Monday after work. Well, I got home, and decided to go there today. They took it in immediately, and the guy at the counter started on it right away. They told me I could have the oversized stud installed, but they just tightened my original back in. I went to the back after it was already re-installed, and he said that he just 'tightened it good', and that it would be alright. He then ran a die over the outside of teh stud to dress the threads, and replaced the nut. While he was tightening it, I watched him tighten it up with a scrench bigger than the one that came with it. So I asked how tight I should tighten it, as it appeard that he tightened it good. I then tried undoing it and it was TIGHT. I tightened it back up, and when I had it tight, he told me to tighten it a bit more as the side cover has a metal bushing in it to prevent the plastic from cracking and distorting. I will run it now as it is, but will look into the torque specs so I can tighten it to the correct specs. Thanks for the tips to take it in.

 

[burnses]

years ago I watched the owner of a shop tighten a set of bar nuts and I couldn't believe how hard he pulled up on em...im sure the torque is listed someplace...just be cautious don't slip and run your hand into the felling spike or chain while tightening....

the can

 

[HarleyT]

I don't like the idea of your "new" saw with this problem, the kid that put together the saw out of the box likely was the one that damaged it,
and I fear that this stud will be a source of future trouble. But, who can say. I would at least get some sort of receipt to document it.

 

[Little Al]

You shouldn't need a " Silver Back brain surgeon"to tighten the bar nut/s the bar adjuster should help to keep the bar in the correct selected position

 

[lil171]

It actually wasn't some kid that put my saw together. It was one of the head people there, and she has lots of experience. My saw was not assembled prior to me being there as I asked for a new one and not the display. As for receipt, I did not get one, but, there is a paper trail as they did it as a warranty claim. I will however follow up with Stihl to verify, and ask for a copy for my documents. Thank you.

 

[HarleyT]

Send me the serial in a p.m., I'll see if they filed a warranty on it.
I am leery of removing bar studs in plastic, they come out easier each time.

 

[HarleyT]

I have had to take several saws that were boogered up by the guy that assembled them, so I prefer to buy them still in the box.

 

[HarleyT]

He is in Canada.
Any members up there able to look it up?