Original Piaggio middle piston ring for liquid-cooled 300cc and 310cc HPE four-stroke engines equipped with pistons manufactured by Asso S.p.A. The ring is installed in the second piston ring groove and plays an important role in sealing the gap between the piston and cylinder while regulating the oil film on the cylinder wall.
The middle piston ring is also referred to as the second compression ring or scraper ring. In Piaggio spare parts documentation, the version with original part number 1A013666 is listed as an oil scraper ring for the second ring groove. The ring therefore supports both combustion chamber sealing and the control of the lubricating oil film during engine operation.
While the upper compression ring primarily seals against high combustion pressure, the middle piston ring performs additional functions. It limits the further passage of combustion gases towards the crankcase and helps scrape excess oil from the cylinder wall.
A controlled oil film is essential for lubrication between the piston and cylinder. At the same time, as little engine oil as possible should enter the combustion chamber. The middle piston ring helps maintain this balance and is therefore an important component of the complete piston ring assembly.
Wear or damage can impair both sealing performance and oil control. Possible consequences include increased oil consumption, excessive blow-by and irregular engine operation. Before replacing the ring, the condition of the complete piston ring assembly should therefore always be checked.
Piaggio HPE engines use pistons from different manufacturers. In addition to Asso S.p.A., Piaggio also uses pistons manufactured by Fujian Huawei Juquan Precision Technology.
The pistons and their corresponding piston rings must be selected according to the specific version. Even with identical displacement and the same engine family, it must not automatically be assumed that piston rings from the two manufacturers are interchangeable.
Before ordering, it is essential to identify which piston is actually installed in the engine. The markings on the piston and the vehicle- and engine-specific information in the Piaggio spare parts catalogue are decisive. The vehicle designation and year of manufacture alone do not allow reliable identification.
HPE stands for High Performance Engine. This designation describes an advanced generation of Piaggio four-stroke engines featuring electronic fuel injection, four-valve technology and liquid cooling.
The 310 HPE is based on the technical concept of the 300 HPE. The main difference is the increased piston stroke. While the cylinder bore remains at 75.0mm, the stroke increases from 63.0mm in the 300 HPE to 70.1mm in the 310 HPE. This increases engine displacement from 278cc to approximately 310cc.
The modifications to the 310 HPE include changes to the crankshaft assembly and engine calibration. However, the piston version actually installed remains the decisive factor when selecting the correct piston rings.
The listed vehicle models are compatible only if the engine is equipped with the corresponding Asso piston version. Vehicles fitted with a piston manufactured by Fujian Huawei Juquan require the piston ring version specified for that manufacturer.
Before installation, the cylinder wall, piston and all piston ring grooves should be carefully inspected. Particular attention must be paid to the ring end gap inside the cylinder and the axial clearance of the ring in its groove. Both measurements must be within the tolerances specified by Piaggio.
The piston ring must not be excessively expanded or twisted during installation. If an installation marking is present, the specified installation orientation must be observed. The positioning of the piston ring end gaps must also follow the instructions in the workshop manual.
During an engine overhaul, it is advisable to inspect not only the individual ring but also the remaining piston rings and their corresponding running surfaces for wear. A damaged piston ring groove or worn cylinder wall cannot be repaired simply by installing a new piston ring.
The original Piaggio middle piston ring 1A013666 is intended for the corresponding Asso piston version used in HPE engines. Clear identification of the piston manufacturer and verification of the correct spare part number are essential for a professional repair.
DE | €
