`Innoviazione nella tecnica classica’ and unbeatable style and design. The VESPA GS150/ GS3 was a milestone in PIAGGIOs engineering history and back when it was introduced, one of the best-selling VESPA models. Regrettably, cooling problems and the consequent heat seizures are much too common. This can now be remedied.
Following the German VESPA veterans club getting in touch with SIP Scootershop concerning this deficit we, in turn, got together with the people at Grand Sport and have been able to provide a welcome update/ upgrade for the Vespa 150 GS piston. The new piston was developed along the lines of the original item, with a very slightly off-centre gudgeon mounting and a suitably shaped piston crown on the transfer side of the cylinder. Y-shaped ribs reinforce the area between the gudgeon pin and beneath the crown of the piston. The material of the piston includes 18% silicium, so improving the transfer of heat and reducing overall friction values. Other components of the pistons material are included to guarantee high stability under load. The piston rings have also been updated to the tougher Grand Sport 1.5mm chromed items. The piston ring groove pins are positioned 48mm apart (chord dimension) on the exhaust side of the barrel so making them suitable for almost all cylinder versions. The 'icing on the cake' of this piston upgrade is the pair of modern piston circlips which are made of 1.2mm thick wire material in a double 'G' form.
Conclusion: If you have been disappointed by the GS150 OE PIAGGIO pistons in the past, this is what you have been waiting for. An up-to-date piston design coupled with high end production and materials ensure first class quality.
Aluminium/ 57mm bore/ 57.4/ 57.8/ 1.5mm piston rings
Aluminium piston, minimum of 18% silicium casting, 30mm compression height, 2 1.5mm thick piston rings made of ductile cast iron, premium quality production with chromed outer contact surfaces. Before assembly check that the piston and piston rings fit correctly.
SIP-TIP: Remember to adjust the jetting of your carb, the ignition point and the grade of spark plug for safe and enduring use of your motor with this piston conversion kit.
SIP community user “Wedome”: “Finally my GS3 runs like it did 50 years ago when new. Piston-cylinder clearance equals 8/100”
Magazine Scooter&Sport, May/June 2011: “It makes you consider buying a GS, just to try this piston out!”