Got what I thought was a good deal on a 2000 Blaster. Ran great, but then I started hearing a slight knocking noise at a certain RPM. Didn't think anything of it. Kept running it around, then it died on me. I started it back up and it started reving up while i wasn't touching the throttle. Drove it a little ways and then I heard a clank. and it started smoking so I shut it down. It was smoking real bad and smelled. Started i back up and drove up to the house and it bogged down and died. Wouldn't restart. Took plug out and found metal pieces fouling it. Cleaned it and ran for a little while then the plug got fouled with metal again. Took cylinder jug off and discovered that the intake side of the piston broke off. Just the bottom part. Also there I looked down into the crank case and could see gear oil. Question is, could a seal have gone bad or did the piece that flew off the piston put a hole in the crank case and cause the oil to run into the crank? Don't really want to tear it all apart if I don't have to. Thanks