The plug part numbers are in my signature. Definitely get them. The idle jet in the rear could be clogged, or the carbs are not synced.
The carbs have to be synced with the bike running, so the front carb could get getting most of the vacuum, and thus most of the fuel.
Wet, gassy plugs mean you're running rich.
1986 Kawasaki Vulcan 750
NGK Iridium Plugs #7803/DPR7EIX-9
Duralast Gold ETX15 AGM Battery
Coastered & Shaved
Metzeler ME880 [110/90-19, 170/80-15]
Balance Dampers Replaced
Rebuilt Forks w/ Progressive Springs
VN750.com Grill Cover
Emgo 23-92411 Handlebars
MOSFET FH012AA R/R
1990 Kawasaki Vulcan 750
1998 Honda VFR800 FI
2014 Honda VFR800F
1989 Pontiac Firebird Formula 350