As midnightsadie says, soldering a a brass float is a workable solution if you can find the hole(s). So is replacing the carburetor, although easier and more expensive. I may catch some heat for this, but, I have repaired non floating air filled plastic floats before by pricking them with a pin, draining the contained fuel and dipping the entire float in phenolic resin, twice. You have to readjust the float height because the float gets heavier but it works and the price is right. It doesn't work well with solid floats that have become fuel saturated.
Chum lee
