Re: Transporting a motor bicycle - on its side...
Spillage from the tank and carb is never going to be a good thing.
Best to have a minimum amount of fuel remaining in the tank, and I would shut off the petcock and run the carb dry before laying it over.
Otherwise, it ain't gonna hurt anything.
I do it occasionally.
My goal is cheap, reliable, personal transport, below the tax collector radar. Fun counts for a lot!