Now that you have it off, might be time to replace. Here is a link to where I bought mine-doesn't reference Kawa 900, but it fit my 2008 Vulcan 900 classic lt perfect.https://www.amazon.com/Bruce-Shark-Yamaha-DragStar-1998-2017/dp/B07VQV1HK6/ref=mp_s_a_1_2_sspa?keywords=bruce+%26+shark+gas+cap&qid=1656013353&sr=8-2-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEzUTFZUVAzWDBWRkJPJmVuY3J5cHRlZElkPUEwODUzOTU0M09XQkU2NTNDNDdVUSZlbmNyeXB0ZWRBZElkPUEwMDEzNDM4MUtLRU9YTlZHQlNRSSZ3aWRnZXROYW1lPXNwX3Bob25lX3NlYXJjaF9hdGYmYWN0aW9uPWNsaWNrUmVkaXJlY3QmZG9Ob3RMb2dDbGljaz10cnVl
For $25 bucks, couldn't beat it. Looks exactly like oem.