The Stage6 Double-Layer air filter insert replaces the original insert and provides greater air passage. To ensure it fits in the air filter box, you should compare your original insert with the one in the picture. When mounting, it is necessary to nozzle the carburetor. When switching from original or standard air filter insert to one with more air flow, you may find that the machine requires more petrol as more air comes in. In order to maintain the right mixture, one therefore needs to check whether it is necessary to re-inject its carburetor.