Main Motorcycle: 2000 Thunderbird Sport
Join Date: Apr 2011
Location: Middleburg, VA area
Other Motorcycle: 1967 TR6-r Trophy
Extra Motorcycle: 2006 Triumph Scrambler
WSC is correct, it is simply an en-richer circuit. My TBS starts perfectly using the full en-richer to start, then I back if off to the point of a slightly elevated idle speed for a few minutes as I ride off.
If your's doesn't start correctly using full en-richer, and in fact starts better when you only use part of it's enrichment, it would seem that either your low speed jet is too large, or your idle mixture screws are set way too rich, or a combination of both??