Since new i have noticed my 17' 250RR fuel tank makes a strange noise every once in a while, even when just sitting in the shop. Sounds like its struggling to release air. After a long hot ride yesterday, I cracked the gas cap this morning and a lot of air pressure released. Just wondering if this is something to be concerned about? I noticed there is a one way valve under the gas cap. Little green part. Any info would be appreciated on this.