Watch out for the middle carburetor on the GT550. The float tended to stick when it got hot and would dump puddles of gas right in front of the rear tire.
Also, A Great Bike? It handled okay for its day and it made a really nice sound but the brakes and suspension were lousy.
I think the green paint job was the best of the bunch.
The GT550 was my first BIG bike. Bought mine when it was 5 years old with 3000 miles and in perfect condition. Rode it 20k miles in a couple of years. Bought a brand new GS750 to replace it.
Current: '13 Sertao, '98 Bandit 1200, '86 R80G/S PD
Past: '66 Suzuki T10, '72 CL350, '74 GT550, '80 GS750, '7? XT500, '83 RM250, '85 XT500