I bought a 2005 blaster about a month ago, it ran good until about a week ago, it started making a weird noise, like a rattle coming from the engine, as if there was a rock inside the engine, and it got louder yesterday. Now when i start it it idles for about ten seconds and then stalls. And will only stay on if i gas it a little. My uncle used it once and he really forced one of the gears to drift, i believe it was second gear, if not first. It still runs, but the noise bothers me. What could be causing the noise?