I made the usual error, I left gas in my mower over the winter. Then thinking I knew what I was doing I drained the old gas and refilled with fresh gas. BUT, not before I messed with the carb settings on the 8HP tecumseh engine. Now the engine starts but has no power under load. It barely pulls me without the blade activated. YES, I know now not to adjust anything without writing everything down. Can anyone help me?