An M21 (1954) I have got going recently seems to have hot oil (or molten grease?) coming from around the head studs after a bit of a run. I don't know anything of the history of the bike but was wondering if this was down to someone putting grease on the gasket when it was last reassembled. If it had valve gear in the head I could understand this but not on a flat head engine like this?
Must have been grease from a recent rebuild as after more riding around the 'oil' has cleared.