Thanks for your reply! No black smoke, and starts easy if it doesn't flood out first. A little history. This winter the engine started chugging and would flood out unless I choke the shut-off valve to almost all the way closed. It was suggested then that I rebuild the carb, and another person asked of the float was leaking. So I took the carb apart and the float seemed pretty air tight. I did order a rebuild kit and changed out almost all the parts except the float, but I did order a new float just in case. It ran great for while after the rebuild, but now it is doing the same thing, after only running about an hour or 2 at the most since the rebuild. I think now I should put in the new float. Also I guess I need to start using the shut-off valve every time I shut down the engine from now on. Another blogger said the gravity siphon flow from the carb will pour into the cylinder heads for a time after the engine quits running. Now that I know this I will use the shut-off valve to kill the engine before turning the key switch off. Any other input is welcome. Thanks to All!