Well today, I was taking my bike out for a spin. And instead of peddaling along with the bike in neutral like I do normally waiting for it to warm up, I gathered some speed, popped the clutch with the choke on, and rode if for about 3 seconds like that then turned the choke off. The bike, to my surprise didn't die or slow down without it being warmed up. I just cruised along like normal without having to warm the bike up at all. But then as I crusied for about 10 or 15 minutes, I realized that when I reach higher speeds a noise starts to erupt from the engine. I can being going relatively fast and then if i twist the throttle even a milimeter more, the noise starts. And if i go back one milimeter, the noise stops. So it seems once i hit this certain speed the noise starts and the bike starts to vibrate. I am wondering if there is something that i caused by not warming the bike up at all before riding it. please, can someone address this problem?