Moto Guzzi Griso 8V 1200 Sump Spacer Gasket Swap (models before 2015) 

The Problem: The upper sealing of the oil sump spacer, can be destroyed over time by the oil pressure. If this is the case, the pump starts sucking air, the oil pressure drops and then ... :-(((
The Cure: Paper/metal gasket B063861
Later Grisos "Black Devil" (not all) and "Red Devil" use the California 1400 sump arrangement and don't have a spacer anymore. These models already have the reinforced paper/metal gasket (B063861) described here.