You might consider this item: GL1100 Carburetor Repair Manual written by noted GL1100 guru Howard Halasz
This Tech Tip is provided courtesy of Howard Halasz – noted GL1100 Guru. Howard is a frequent contributor of technical columns and other information to GWRRA’s Wing World Magazine.
“A common failure with all GL1100s is the vacuum advance part of the pulse generator assembly. The units for the 1980 models use a higher advance angle than the unit for the 1981-1983 models.