Predator 3500 Watt Inverter Generator Vented Oil Fill Cover Replaced By Yuxuan Some early model generators were so well sealed that the engine could not get enough air.This would cause a surging condition so the fix was to remove the oil fill cover. This new cover, will allow you to have a cover to keep large debris out of the This door is meant to fit snugly, forcing it in could cause the tabs to break INCLUDES: Oil cushion cover door, basic washable filter, no hardware; Printed on PETG plastic, this new pillowcase allows you to have a cover to protect large pieces. Some early model generators were sealed so well that the engine couldn't get enough air. e Some early model generators are well sealed and the engine cannot reach enough ai engine area, while still providing adequate air circulation.