Do you want to keep it that way for improved airflow, or do you want to fit a lid?
It's not unheard of to runwithout a lid - just tywrap the filter in place - though in my experience, it makes the bike very LOUD!
Just make sure you re-jet accordingly.
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MC21SP Plaything
BMW F800GS Bumblebee
Triumph 9551 Daytona Big boys toy
FJ1100 Sporting relic
GTS1000 oddball