I drove 2 hours Monday one way to get this mower. Since them I have replaced the fuel pump and rebuilt the Carb. Once I got the engine started it resembled a freight train. I think it was burning more oil than gas. My next door neighbor had a 15 hp Kohler Command single cylinder. I went up and snatched it up. Going from a briggs to a kohler is always a challenge. From the factory they put Kohlers on these mowers because factory bolt holes where already there. After figuring out the wiring (everything works like it did with the briggs). I did have to install a new wire due to the kohler having a Carb solenoid. After doing all of that work yesterday I came in because I was tired. My thermometer read 98+ the whole time I was in my building. I even have it where both tanks work. Well today I went outside and started her up. Pressed reverse on the hydro handle (which is wooden) and nothing happens... Of course.. I forgot to disengage the hydro override. After doing so the chain sprocket will spin but the axle won't spin. Anyone have any idea what it could be?