Richard Rice

I have a 2018 HD 8 Defender with several problems. It has 281 hours and 137 miles and has rarely been in dusty or dirty conditions. The problems: (1) Gas appears to be getting into the oil and diluting it. (2) When idling after some use, I can smell raw gas, (3) It backfires and pops going down a hill with foot off the accelerator. (4) It cut out, popped, and almost left me stranded while crossing a four-lane highway. Any suggestions?