I usually run mine dry at the end of a flying day since they are stored inside the house, so it takes a bit more choking on the first flight.
Whether it makes a difference or not, it seems to me like they pull fuel better if the throttle is wide open and the choke on. So first flight I choke it with full throttle for 10 flips, then I close the throttle to just barely above closed as I can't hear what I call "the snotty nose" sound when the throttle is wide open. It's usually apparent within 5 flips of closing the throttle when I hear that sound. Choke off, ignition on and they go the next flip, on rare occasion two. This method works on both my 50 and 100.
While flying the 50 yesterday when it had sat long enough to cool off completely, 1 choke flip, choke off ignition on and 1 flip to start.
And yeah, when you change the oil brand/type (syn or dino) or mix ratio, you have to re-tune. I won't get into the brand/type debate as I've settled on a particular brand/type after trying number of them, but suffice to say it's a 40/1 mix....
