Ok guys....essentially these things have 4 carbs within two bodies....I can see how you sync the two bodies, but can you, or do you even need to, sync the carbs in each body? Mark
You only sync the 2 bodies... the rest of the syncronising is done with the mixture screws and that is explained in that article... at the end. You do it by Temperature on each exhaust or you do it with vacuum gauges... It is super important to Sync the 2 bodies first and the only way to do that is with the carbies off... using a fine drill or other item to check that the butterflies are as close to being exactly the same as possible.
This look's to be pretty good info too, https://www.scribd.com/document/97781950/1-55-Carb-Sync-Tool-by-Marty-Ignazito