The one under the sticker is the 'pilot jet'. It has been reported that replacing this jet with a larger one improves overall performance.

There may be a detailed 2 part rejetting post..it details how to remove the jets and "bore" them larger using drill bits (very small ones that is). I have rejetted my Duraforces and the performance is remarkably improved. I am sure that Toro would have wanted larger jets too, but regulations probably prevented them from doing this and therefore the engines are running starved of fuel. It is a highly recommended upgrade. On other posts, there is discussion about using another Toro jet from the proline that will fit and has the larger jet. I dissassembled my carb and bored both high and low jets. While others have had success just removing the one (under the sticker) and boring.

Thanks guys. I finally found the rejetting post. I have not tried this yet, but am planning to. What I did do was give the governor adjust 8 clicks clockwise. (5 at a time, then back 2). I also cleaned the pilot jet orfice with a thin wire. This worked like a champ!! Before doing so, I had to run the mower in the choked position. There was absolutely no speed control. Now it idles both in "rabbit" and "turtle", with barely noticeable surging.

Great job guys!