Smell of gas coming from exhaust?

i own a repair shop ,and you need to take it and have it put up in the air,and look around the tank area for it,theres a small possibility it may have a tiny pin hole in the gas tan on it causing this to happen,and that might be what your smelling,either that or a loose hose on it ,either way it needs to be checked out really good,if its raw un burnt gas its dangerous to drive it like that,good luck i hope this helps.