We just bought a bx2670 and its a awesome little tractor. I was out mowing the ditch and when your mowing the length of the ditch and the tractor is tilted to one side i noticed it starts to run rough. I thought it was the shaft driven mower deck so i disengaged the pto and it was still running rough and shaking and as soon as your level it runs fine. I had a full take of fuel also. Thanks