The gasket was on a 2004 gasser around 2014 with a del orto. It was the std gasket for the needle valve.
Ethynol is terrible in Keihin carbs due to the passageways in the jet tower.
https://advrider.com/f/threads/keihin-death-barble.1285977/
I recently sold my Beta. Now ride a TRS. My son just bought a left over 300rr. We do not run ethynol in anything, but our cars.