So my stone metal has been occasionally making an engine squeaking noise. It isn't super loud, and doesn't happen on a regular basis. Sometimes it happens when it is warming up. Other times it happens when I am riding. It is peculiar to me that it is so unpredictable on when it happens. it sounds similar to when i have had a loose belt on a vehicle before. But the guzzi is chain driven, so I am wondering if it is that. However when I have had a loose belt, it has made the noise on a regular basis, where this does it sporadically. Any suggestions on what it may be?