The larger R/R is probably a good thing.
0) Test and charge the battery. Check all connections.
1) Run through the electrical tests stickied in the electrical section. You want to do a full work-up of your stator and R/R.
If everything is wired properly, I am betting your stator went south and he didn't feel like repairing it.
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