Fuel left inside an engine for longer than 30 days begins gumming up, forming a varnish-like material that clogs up the small jets and ports in the carburetor. To clean the bowl, use carb cleaner and scrape out the varnish.
Often it’s easier to completely remove the carburetor for cleaning. Start by removing the choke lever. Unlatch the governor link and the tensioning spring with needle nose pliers.
After lifting the float, the main jet in the carburetor is visible. The jet’s passage is where fuel flows through the carburetor into the combustion chambers. To inspect, remove the jet with a flat blade screwdriver.
To open the passage of the jet, spray carb cleaner on it and use one bristle of a wire brush to insert and clear out any particles or gummed fuel. Be careful not to make it any larger than its original size.
The limit cap is part of the tamper-proof system required by the EPA. It is a non-serviceable part, so handle it with extra care.
Clean the main nozzle passage until it’s free of grime. Be sure the holes on the sides are open and clean as well.