The carburetor float needle is either sticking or not sealing properly. Take the carb apart and clean it and look for a indent on the needle tip. if it has one, it most likely needs to be replaced. You have two options if this is the case: #1. find a carburetor rebuild/overhaul kit #2. Buy an aftermarket carburetor from Amazon etc. that is supposed to fit your model and take the needle and any other parts you may need from it and install on the OEM shell. Please don't actually use the complete aftermarket carb, only the parts you NEED, because they usually aren't the best quality (they have a tendency to cause surging and run rough) and you will probably have to take the carb apart again. This method has worked for me personally several times with no issues.