You need to drain the fuel and remove the carburetor. I would get a good carb cleaner then the most important tool you can have: you know those little ties from bread bags? Strip the paper off, and you have the best carb jet cleaning tool known to man. You should look on YouTube to see if there is a video for your particular model on how to break it down, but they are generally not that complicated. Zap the parts with carb cleaner and use that little metal piece to clear the jet nozzles. I do this every year on my mower and 4 cycle weed wacker. Works like a charm. As an alternative, you can just replace the carb. Most shops now do not break down and clean carbs because it's cheaper to buy a new one than the labor required to troubleshoot, clean, and re-install an old one. You probably got crap in your carb from the crap in your air flow. It's important to keep a clean air filter to help prevent junk from getting into your carb when it draws air into it.