Air ox Delete Carb Issue

[Imo690]

I have an airbox delete fitted to my 1979 R65. Now that the carbs are only mounted at the cylinder inlet end, they tend to loosen over time when my boots catch them. I’ve sorted out the right-hand carb by extending the brake pedal. Anyone else come across this issue and how did you resolve it? A lip on the inlet would work as would mounting a couple of small springs. Happy to take any thoughts. TIA Brian