I bought a 2015 Monster 821 with 3k miles. Zero issues other than coolant leaking from the overflow tube when sitting in traffic randomly only after the fans have cycled. The bike never overheats and almost immediately stops once the bike starts moving again. Is this just an air pocket or possibly something more serious? I also noticed once I pulled over and turned the bike off I could feel bubbling through the overflow cap. Thank you for any insight.