I bought a new to me exmark today. The story I was told when I bought it was that it had a bad head on the motor and the motor would need to be replaced. When I got there the motor started fine and ran and sounded great. The problem was it would not hardly even pull itself around on flat pavement. It didnt really sound like a motor problem to me more like a hydro problem. So I bought the thing and brought it back to the shop. After playing with it for a while I found these two little plugs or whatever on the hydro motors that were loose. I tightened them up and now she seems to run great. So my questions is what was this thing that I tightened, and here are a few pics, the last two are of the thing that I tightened up. I have always had ferris so I am lost with this one thanks for any help and let me know what you think of the mower.