TECH TORQUE: DELL’ORTO SH CARB STRIP AND SERVICE

When Innocenti launched the Series 3 Lambretta towards the end of 1961 it had many changes and new components. Though the engine remained similar in layout to its predecessors, one of the upgrades was a new style of carburettor. Manufactured by Dell’Orto, it was called the SH series and was much smaller and compact, featuring an internal float bowl. It was fitted as standard equipment to all Lambretta models until production finished with the GP in 1971. Availability came in three different bore sizes: 18, 20 and 22mm. All had the same layout of jets, atomiser and float and all ran the same style of air filter. Fuel consumption was very economical and, if serviced and maintained regularly, very reliable. Though many Lambrettas use the modern PHBL series carburettor, many still have the SH fitted. Servicing is required certainly if the engine hasn’t run in a long time but due to its fairly simple design and layout it’s easy