Firstly, Piaggio / Gilera / Vespa engines are mainly split into three different types, all produced by Piaggio: Pre 2000 Piaggio / Gilera engine – No catalytic converter and Dellorto or Weber 12mm carb 2000-2005 Piaggio / Gilera / Vespa engine – Catalytic Converter and 17.5mm Dellorto carb 2005 onwards Piaggio / Gilera / Vespa engine – Catalytic Converter, 17.5mm carb and slightly lower exhaust port There are minor differences between the Piaggio 50cc engines (which is the same motor fitted in every Piaggio, Gilera or Vespa 2 stroke 50cc machine produced, e.g the Piaggio NRG MC3, Gilera Runner, Piaggio Typhoon, Gilera Stalker, Vespa ET2 50cc, Vespa LX 50cc, Piaggio NRG Power etc) but no real major differences between all the engine versions, just mainly setup changes with the introduction of the catalytic converter into the Piaggio / Gilera / Vespa Exhausts The pre 2000 engine came with no catalytic converter and a 12mm carb fitted. This engine is getting on a bit now, and there aren’t that many bikes left on the road with it, although I’ve seen more Gilera Runners still about at that age, so I presume they sold a lot better than anything else. Derestricting this engine is ...