Troy Bilt- stored UPRIGHT (nose down) over winter. NOW I know that was the wrong thing to do, but did not then. Started it this spring, smoked something fierce (yes I now know OIL was in the cylinder.) I let it run a short time, and it just seemed to keep getting worse- meaning, oil smoke slowly dissipated, but the mower slower ran worse and worse. Sounded to me like fuel flow or carburetor issues. My question is- what should I do? Is it possible that just a carb cleaning will fix it? Could the running it the first time with oil in cylinder top ruin the cylinder/rings?