Nice to see some good information coming out even with "the Wolves circling".
What one needs to consider when you defend a particular part, or parts, and throw a few rocks at the operator, and the messenger in this particular case, is that this is a relatively "low end" Stihl saw, and targeted at the "homeowner", not a professional.
Even though the saw is two years old, it has only a few hours run time on it. WHY would the air cleaner be loose and falling off of in the first place? It was flopping all over the place, as the snaps were spread wide enough only one was attached at any particular time. This would allow a LOT of unfiltered air into the engine if not corrected. The homeowner had never even had the cover off of it till yesterday.
This particular homeowner is a great guy, a good neighbor, and obviously a pretty smart guy with several degrees. He bought a Stihl chainsaw because of the name, and reputation, no other reason. He obviously doesn't use it very often, once or twice a year at most. So back to my original comment/observation:
IF setting or trying to set the choke without pulling the throttle FIRST causes that little spring steel stop to find it's way under the switch, that's just not a good deal all the way around.....IMHO
Then Mr. Homeowner pulls the cover off and starts pissing around with things he has no clue about, and ends up driving to the dealer to get a 30 second lesson in how to put the spring steel part back on top of the switch. Come on guys, Stihl can do better than that.
Does anyone on here really think the owner of a casually used saw is going to pull out the owners manual before trying to fire it up, once or twice a year? I'll bet my next months pay they are going to go right for the choke and the pull cord.
Cripe, Winter would be over before I could even find an owners manual for one of my saws!
For the guy asking about the 028WB, nearly as I can remember the saw was deemed by the dealer to need considerably work (he actually recomended junking it) simply because a spring in the air cleaner was allowing the choke flap to suck shut at full throttle/load. It's been nearly a year since I worked on that saw, but I distinctly remember a small spring and some sort of choke flap as part of the air cleaner assembly. The repair was easy, I installed a new air cleaner assembly, the spring was much stronger and didn't allow the choke flap to suck closed when the saw was in use.......Cliff