The item "Piston rings Delta 70 + 1.00 KOSO" is a set of piston rings for Delta mopeds. The rings seal the piston in the cylinder: they hold compression and keep oil out of the combustion chamber.
Replacement is needed when compression drops, hot starts are difficult, oil consumption rises, and there is bluish smoke. The size is chosen by piston diameter. "+1.00" in the name denotes an oversize: the ring diameter is larger than standard by this amount in millimeters. Manufacturer: KOSO.
