Stihl MS391 Cover Screws

I've had that cover off at least a dozen times, and the screws always stay in the cover, so I suspect the plastic mouldings in the cover, which are supposed to retain the screws, failed. The Stihl tech who replied via e-mail indicates that there should be no problem covering this minor problem under warranty. I guess from now on, when I am using the saw heavily, I will check these screws for tightness every time I take a short break...and I will probably put some threadlock on them, as well.
 
Why wouldn't you act like a normal human, and leave the cover and the screws alone????? Or does Stihl have to pencil in an obsessive disorder clause on their new saws? Just curious......
 
Fish said:
Why wouldn't you act like a normal human, and leave the cover and the screws alone????? Or does Stihl have to pencil in an obsessive disorder clause on their new saws? Just curious......
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Sorry, I am off my meds....
 
Fish said:
Why wouldn't you act like a normal human, and leave the cover and the screws alone????? Or does Stihl have to pencil in an obsessive disorder clause on their new saws? Just curious......
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If you ever had the opportunity to look at this model saw, you would see that this service cover supplies access to the air filter, carb, and spark plug. If you have anything constructive to add to this discussion, please do. Otherwise, if you are just using this forum as a means of entertaining yourself, and displaying your obvious lack of knowledge, your time would probably be better spent elsewhere.
 
There are lots of guys that think they know all on this forum, I think he will get the idea now. I posted some pictures of my MS391 that show the screws, are they like yours?
 
deminin said:
I've been helping a neighbor cut down some trees to make room for a workshop. Today, I had a strange experience. There are (3) 6MM screws that hold the top cover...over the air filter and cylinder head in place, and today 2 of them popped out and got lost somewhere in the dirt and debris. I take the cover off every time I use the saw and clean out the air filter area, etc., real good. I tighten these 3 screws good, but today good apparently wasn't good enough. These screws are "captive" and shouldn't just pop out, even if they come loose. Naturally, I can't find a parts breakdown online, and I doubt the dealer has something like this in stock, but I will be going over there in a couple of days to see. The saw is still under warranty, and if there is a problem with these screws working loose, I may just request a whole new top cover....we'll see what he says. If anyone has a parts list for these saws, could you see if there is a P/N for these screws. Thx, in advance.
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Your top cover is broken then, I have the exact saw and that is how you access the twist lock filter and they are designed to be removed and service you saw.
The screws have retainers in them to keep from coming out of the cover.

Edit to add: Apologies should have read the entire topic and discovered you had already confirmed your saw had an issue before posting.
 
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