A leaky injector might give you those symptoms, as the fuel system stays pressurized for some time after shutdown. If the leak was caused by a tiny bit of debris that was later dislodged, the smell issue could cure itself. If the smell returns, remove the air cleaner and inspect the intake tracts for evidence of neat fuel.
Also possible the O rings on the injector bodies themselves can leak, but less likely here as you would see some fuel residue or staining. O rings can be replaced with generics from the local parts store, btw. But if they're not leaking, leave them alone.
