The gasoline in the carbs evaporates very quickly, so your leak could be from one of the 6 carbs.
Alternatively, but less likely, it could be a leak from the oil supply line to the OMS pump, if you are still using oil injection.
The only way to find it is to look.....When motors are tilted up, the carbs often leak. This can wait until you tilt it down again, to leak out.