Help with translation on A6M cockpit Fuel primer/pump

[beretta1934]

Would like to know what the kanji legend on this rare item reads. Appreciate your help!

[chen]

That thing looks look either the fuel primer or throttle or mixture control.
I guess it alerts the pilot to remember after use, turn in the appropriate direction so that it stays locked and won't come out.

[beretta1934]

Thank you very much Mr. Chen!