People tune real engines using this data. So one simple rule applies here: no value is invented, estimated or “plausibly filled in”. Gaps stay visible, contradictions are documented rather than decided.
Primary sources
- Dell'Orto application catalogue, printed edition 12/1990 (“Regolazioni carburatori per motoveicoli”) – our own copy, photographed page by page and transcribed.
- Dell'Orto carburettor data “Moto Speziale” (German-language factory table, as of 16 June 2007), available via thisoldtractor.com (Gregory Bender).
- Original workshop manuals and parts documents from the archive guzzitek.org (“La Guzzithèque”) – for cross-checking and for gaps.
- Dell'Orto technical documents via thisoldtractor.com for tuning method and nomenclature.
How it is checked
- Every record carries its source including the exact location (catalogue page/row or manual chapter).
- Values are read via the Dell'Orto part numbers – they act as a checksum against column shifts.
- Where a second photograph of the same catalogue page exists, it is read independently as a cross-check.
- Deviations appear as “factory sources disagree” right next to the affected value — with both figures.
- Unclear cases are not published but flagged internally for review.
What this means for you
“–” means: not fitted on this model, or not documented in the source. Factory data applies to standard condition; after modifications there is no way around your own tuning session (here is why). Found an error? A short e-mail is enough — a source reference helps.