Saw update. I replaced the Stihl 210 with a Dolmar 421a few weeks ago. Great little companion for the 6421. No more Stihl, no more flippy caps. Life is good. 421 has 1hp more, just what the doctor ordered, great little limbing saw. I've actually been using it in bigger wood than I had planned due to the light weight and its abilities. If anyone has been considering a 421, you won't be disappointed.
I liked the flippy caps at first, but after a few fill ups unless you blow em off first you tend to get more crud in your tanks. I'm going to start carrying a can of ether or something to spray around the caps before taking them off if a air hose isn't handy.
Always have a paint brush with me for that exact purpose. Unfortunately, that is the least of my concerns with a flippy cap. They just #### me off all the way around. They are a solution in search of a problem. Aside from the fact that they suck to get locked if you overfill by three drops, they leak, and they fall apart. Now why in the world should a cap be built to fall apart?
Mlappin- I love the 120super and the si. 120si is the one that sold me on the Dollys 20 some years ago. Would love another one some day. Don't know why I ever parted with the first one. Good old saws. I was logging at the time, can't even begin to guess how much wood that saw went through, and NEVER so much as had a hiccup or a burp.