I would try pulling the carb off and giving it a thorough cleaning. A rebuild would be nice but personally I'd just try a good cleaning first. Of course I'm cheap when it comes to this sort of thing. I disagree with the "always" needs it. My current 20 horse is just one of many carbs that I've gotten to run without a rebuild. I don't know how long this one had sat because it came from an estate sale. But the motor was in pieces with a few pieces and lots of bolts missing. I cleaned the carb and finally got it put back together and it runs great.