G1 1979-1984
Yamaha 2-Cycle oil injected engine

G2, G8 1985-1989 and G9 1990-1993
Yamaha 285cc 4-Cycle OHV Engine

G14 1994-1995
Yamaha 300cc 4-Cycle Engine

G16 1996-1999
Improved Yamaha 301cc 4-Cycle Engine

G22 2003-2006
Yamaha 357cc 11.4 HP 4-Cycle Engine

YDR (The Drive) 2007 up
Yamaha 351cc 11.4 HP 4-Cycle Engine

Check out the Yamaha Golf Cart timeline