Lambretta Dellorto SH1/18, SH1/20 and SH2/22 - the carburetor series at a glance

Lambretta Series 3 Li, Special, TV, GT, SX and DL / GP (125, 150, 175, 200cc) and the lui 75 carb settings

The Dellorto SH1 and SH2 carburettors were integral components of Lambretta scooters, particularly the Series 3 and GP models, known for their reliability and easy set-up. Below is a detailed overview.

Sizes and Applications:

The SH1 series was available in 18mm and 20mm bore sizes, designed for Lambretta Series 3 scooters such as the Li 125, Li 150, and Li 150 Special. The 18mm version was typically fitted to the Li 125 and Li 150. While the 20mm SH1/20 was used on models like the TV 175, TV / GT 200, SX200 and the Special 125.

Design and Features:

The SH carb series featured a simple, robust design suited for the two-stroke engines of Lambretta scooters. They used a slide valve mechanism to control air and fuel mixture, with standard jetting configurations tailored to specific models.

Detailed view of carb and parts names:

Maintenance & spare parts

Availability: Both SH1 and SH2 carburettors are available as new parts and they are supported by a wide range of spares, including float needles, gaskets, jets, and atomizers.

Standard carb jetting listing:

* On the Special 125 a variety of main jets was tried during the production, beside the listed 99 also 103, 105 and 107 main jets. We found that a 107 in combination with a 5899-5 works best on a standard engine.

** The dl / GP 200 was also delivered with a 123 main jet.

Jet parts and components in detail

• Idle jet Dellorto type 3360 (sizes 30-60):
  To the product "
• Main jet 5 mm (Dellorto):
  Single "
  As a set from BGM with even bigger sizes than intended from Dellorto"
• Mixing tubes (atomizer) - Casa Lambretta:
  To the overview "
  
• Jockey's Boxenstop slides, the larger cut-out on the back gives a leaner mixture for smaller engines:

This is the SH atomizers - briefly and concisely explained.

The bigger diameteres the holes have, the leaner is the fuel/air ratio at the given RPM.

Buy complete SH carburetors as new parts:

• SH1/20 carburetor (item no. 3332032) "
• SH2/22 carburetor (part no. 3331984) "

Original Innocenti part numbers for Anoracks:

• SH1/20 for DL 125: 00412484
• SH2/22 for DL 150: 00412483
• SH2/22 for DL 200: 00412485
• SH1/18 for Li 125, Li 150, LiS 150: 00412441
• SH1/20 for LiS 125, SX 150: 00412442
• SH1/20 for TV 175, TV 200, SX 200: 00412443
• SH1/20 for lui 75: 00412461