Hey everyone! I have a 2013 RMZ-250 and just recently notice a "knocking sound" in the engine. I am new to dirt biking and not a mechanical genius outside of changing the oil, tightening spokes, maintaining the air filter and other little things. All self taught by means of motocross magazines and videos on Bike Bandit and a few others. I can't do any substantial engine work so I have no idea what this may be, then maybe I'm just hallucinating and it's normal and it always but I just noticed it. Regardless, can anyone offer some insight. The bike has about 60 hours, and has not been ridden hard at all. I really care for it and just love it! Sure I've dumped it a few times but nothing really bad. I have not adjusted any valves or done any piston work. Could it be the gas (93 octane), valves or piston? Is it normal? I'd really appreciate some input. At 43 this sport has really become my life!