I was cutting the sides of a drainage ditch that had slopes of over 45 degrees. I noticed that my 12HP Kaw valves started to ping. I immediately went down to the bottom of the ditch and pinging went away. I then tried to do the slope with the oil filter side of mower on the low side and that seemed okay. So now I am wondering if it okay to run on these slopes with the oil filter side down or is that bad also.