In my case they did. Here's the variety I've tried. All resulted in issues. Basically there are two problems a float valve can have. A needle that's sticking in the valve. Tapping can help. Also a fuel system cleaner additive can help. A needle not perfectly shutting the valve is the other problem. A tiny particle of dirt can cause this. Again: tapping and flushing by opening the drainscrew and opening and closing the petcock. With the OEM fuel filter in good order, there's no need for any extra filtering.