Dellorto carburetors can be found on moped brands such as Tomos and many Italian makes like Intramotor Gloria, Vespa, Benelli, Pacer and Garelli. Dellortos are also a popular carb to retrofit for Motobecane mopeds.
Popular models used on mopeds include the SHA series and the PHBG series.
The SHA Series is a flatslide carburetor with a hand or cable choke with fuel adjustment limited to the main jet. The SHA series comes in the following sizes 9,10,12,13,14,15 and 16mm. Many SHA series carburetors have two internal diameters such as the SHA 14/12. The bore diameter is 12mm at the choke opening and 14mm throughout the rest of the carb. The SHA carburetors found on Vespa models are a special low profile design and come in 9-13mm bore sizes. The don't share parts with the regular SHA carburetors but use the same jet type. SHA carbs take 5mm Dellorto jets (same as PHBG). For more info on function and tuning see: Dellorto SHA
The PHVA Series uses a round slide with needle, has 3 jets and an idle mixture adjustment screw. It can be equipped with a lever, cable or electric choke. It can be found on Tomos models with the A55 engine and many scooters. PHVA carbs take a 6mm main jet -- PHBG and SHA main jets will not fit.
The PHBC Series shares its design with the PHBG series but uses a different style choke lever. This carburetor is said to be somewhat popular with tuners in Europe.
The PHBG Series carburetor is popular on racing mopeds equipped with big bore cylinders.
The PHBG is a round slide carburetor with mixture adjustment, adjustable needle valve and three replaceable fuel jets. The PHBG has a main jet, starter jet and idle jet. The PHBG carburetor can be found in sizes 15-21mm. PHBG carbs take a 5mm jet (same as the SHA). The PHBG can be equipped with a hand choke or a cable choke and can be equipped with a male or female intake connection. See also: How To Tune PHBG Carburetors and PHBG tuning made easy. (a step by step guide). Also here is a detailed description of PHBG parts from an aprilia forum Carb Parts and Functions
Note: If you run a PHBG, it is recommended that you check the atomizers first before installing the carb; Dellorto supplied shops with some PHBGs with four-stroke AN atomizers, and the 9562 AN type atomizer bushing. If the atomizer part number starts with AN, it's a four-stroke atomizer, and it may be more difficult to tune and run very rich at idle and too lean at the 5/16 throttle position on piston port engines. All two-stroke atomizer part numbers start with AU and use the 9655 AU atomizer bushing. For more information, please read this.
For information on Dellorto tuning, check out the manuals here.