Yes, it is the yellow damper on the bottom front of the saw. It's on the opposite side of the spring.
Mine had a huge split in it that was letting the handle hit the back of the main baffle, just under the filter cover.
I still like the saw, and even considered buying another. If I don't like the vibes on the 440 (now that I'm spoiled) I would consider another 441.
Congrats on the new saw. I'd be lying if I said I wasn't a little jealous. (been looking for a new one reasonbly priced).
A lot of guys are going to hate me for this, and let me start by saying that I love my 440. It is a light 70cc that runs damned good with the dp cover.
The 441 is more of a saw. It wieghs a little more, but it is more HP, more (broader) torque curve, less vibes and a heck of a filtration setup on it.
I believe you will not be as happy with it as you are with your 441. Guys that ran the 441 before the 440 can't stand the 440. Guys that ran a 440 from the get go, can't stand the 441.
Truth be told they are both great saws, but the 441 is a nicer saw all the way around.
here's my thoughts on your 440 questions:
For the HD Air filter, just check it every couple tanks. It isn't bad when you are cutting clean wood with a sharp chain, but when the chain dulls just a smidgen and the wood is a little dirty. the filter will need more attention.
The A/v is not bad at all imo, but it isn't near as smooth as the 441.
I have 4 70-80cc saws and love every one of them. The 440 is not the most powerfull one out there, but the extra light weight (for a 70cc saw) and good power make it many peoples' favorite. The 440 and 7900 are my go to saws.
If you seriously don't like it and want a 441, I will take the 440 off of your hands.