In the literature for the Gen 2 GYTR Turbo kit the PN is shown to be BAS-E4451-V0, however I was told the filters PN that actually comes with the kit is BAS-E41C0-V0? Not sure which is the case, BUT you can try these links for the latter:
Buy Yamaha BAS-E41C0-V0-00 - GYTR TURBO AIR FILTER. This OEM part is guaranteed by Yamaha's limited part warranty ✓ FREE Shipping on qualified orders - Boats.net
It seems for most all of this GYTR specific piece parts from a kit, it is a pain to get. If you cant source it anywhere online I'd call your local dealer and get them involved with needing a replacement. I've been told for specific parts to these GYTR kits that it usually takes them confirming you either bought the kit from them/elsewhere and trying to cut through a bunch of red tape with Yamaha. You'd think it would be a bit easier to do with a consumable such as an air filter, but you never know. Good luck.