Hello, I have a Sears 28" Craftsmen with a 9HP Techumseh engine manufactured in 2006. Had it in recently for repair and had the carb cleaned and a leak around the carb sealed. Additionally, the engine was 'screaming' at full throttle so the governor was adjusted. I was told the valve cannot be adjusted. Anyway, It ran for 3 minutes and stopped. So, I'm thinking would a new carb help or is it time for scrap it? Thoughts?