So I was riding this weekend and everything was going good. I was prolly two hours into riding coming up a hill full throttle and I here what sounded like a rock hitting the bottom of my quad. Could have also been a backfire but and not sure. As soon as it happened my engine stopped.There is absolutely no damage anywhere underneath or on my quad.

​​​​​​I Got it pulled back to camp and stated diagnosing. I'm getting fuel and I'm getting air. I see no reason as to why I would not be getting spark. Pulled the plug I put in brand new two days prior and it wasnt fouled or anything. When I pulled the air filter and box, I had some black stuff in the air intake of the carb. Not a lot, also the filter had black stuff on it and smelled a bit like fuel or oil. Also checked my fuel it was getting fuel at least to the carb. I'm gonna do a deeper dive when I get back home but just wanted to see if anyone had any thoughts.

The only thing I changed was I put some premium gas in the quad from my buddy because I had ran out. My concern is the loud pop and immediate loss of engine power. It will still crank but won't turn over at all. I was thinking it may be possible that the oil mixer went down and something internally in the engine went bad. The mixer has worked fine but I know the reputation and I know I should have done the bypass along time ago. Anyone else have this happen when there mixer went down? If it is that, how screwed am I?