Hey guys, My XT 225 (same motor as ttr 225) knocks when I first start it if I rev the motor (a little) without letting it idle for a bit.. I checked the oil level and it's at the top mark when warm when balanced out so not an oil issue? It almost sounds like a dry start, or maybe the sound is a little piston slap or cam chain slap?. The bike has over 5000 miles on it now and I changed the oil every 500 miles. If i let the bike idle for a few seconds first it doesn't do it.. Is it normal and I just need to wait for the oil pressure to build up? I don't remember it doing this when I got it, I just want to take care of my bike the best I can.. Also, the valves are due in about 500 miles if that makes any difference - here's a short video, it doesn't last any longer than how long the vid shows it for.