My 420 rancher was just purchased back in may, so it's been lil over a month I've had it it's brand-new had .1 hrs on it when I got it it now has 346 miles and 39 hrs on it. I've been having problems with it backfiring sometimes and the muffler blued out almost instantly. I rode it maybe 25 miles and it was a bright metallic blue color. I didn't know it wasn't supposed to do that, well I had first service done and everysince I have had to put 3 sparkplugs in it for it to run like it should and now I changed my oil and found that gas is mixing with my oil I don't understand what's going on it is under warranty and I've taken it back but the first thing they asked me was has it invested any water but it hasn't. Any ideas on what's going on here?