I just bought a used piaggio ciao that does not run. I showed it to my dad and as pedalling he said, "it sounds like there is air leaking from the cylinder." there was a hissing noise when we pedalled it. Is this normal? also, I would be interested in buy a manual for it, so please contact me if you know about one. What is the oil to gas ratio for the fuel? Also, if anyone knows any specific information about the ciao, I would greatly apprecate it. Thank you!