The Yamaha jetting instructions state to run their recomended jetting with the filter cover off.
I did that and ended up with a airboz full of sand untill I found this, The EHS Air Box Cover.
Thanks to Meiko the Cat holding BoxCover in place
Note the filter is framed in quality billet aluminum as is the cover over the snorkle hole. The genuine Outerwear filter is correctly edged and installed smartly.
Choice of colors, and you can get the kit to build it yourself with your own airbox cover, or they'll send it to you complete.
Our 2 EHS covers arrived in excellent condition, remarkable quality