The FAA issued an airworthiness concern sheet for old-style fuel selectors on Piper PA-28-140, -150, -160, and -180 models as well as PA-28R-180 and -200 models. The generation 1 fuel selectors in these models do not include protection from unintentional misaligning of the selector nor do they prevent over-rotation, which could result in inadvertently selecting the off position.
The agency had previously issued an airworthiness directive requiring owners of models with generation 2 fuel selectors, which were factory installed after 1971, to update their aircraft to the current generation 3 iteration, but it did not require upgrading generation 1 fuel selectors. Owners with the serial numbers specified in the ACS who have the first generation flat-plate fuel selector installed are asked to notify the FAA of any operational concerns with the fuel selector.
Read the concern sheet here.