Suzuki GS550
Years produced: 1977-1978 (1st generation)
Claimed power: 49hp @ 9,000rpm
Top speed: 111mph (period test)
Engine type: 549cc OHC air-cooled inline four
Transmission: 6-speed
Weight: 431lb (wet)
MPG: 42-45
Price then: $1,745
Price now: $750-$2,000

As the last of Japan’s Big Four to introduce 4-stroke engine technology to its lineup, Suzuki clearly appreciated that when it finally went up to bat against the other 4-strokes with the Suzuki GS550, it needed a home run.

There was no question that Suzuki would have to enter the game. While 2-stroke engines had served Suzuki well in a host of road bikes, including the classic 500cc Suzuki Titan twin and the Suzuki GT750 and 550 triples, the buying public was increasingly shunning smoky and often peaky 2-strokes for cleaner-burning, quieter 4-strokes. By 1976, every one of the Big Four except Suzuki was producing a range of 4-stroke fours. Enter the new GS line for 1977.

All new machines with all new drivetrains, the Suzuki GS550 and its big brother, the Suzuki GS750, were Suzuki’s answer to the 4-cylinder, 4-stroke equation that was defining the middleweight and heavyweight classes. Covering its bases, Suzuki also introduced a small-bore, 398cc 4-stroke twin, the Suzuki GS400.

The bigger 750 was an instant hit with buyers and was Cycle World’s pick for its annual Best of Breed in the 750cc class. Reviewers and riders alike raved about the new 750, yet while the smaller Suzuki GS550 was essentially a scaled down 750, it failed to capture the same level of attention, at least from the motoring press.

A better middleweight
It could be that the Suzuki GS550 simply didn’t have enough flash. True, its styling might have been somewhat subdued, but at a claimed 49hp it was no slouch, with quarter-mile times in the sub-14 second range. That put it ahead of Honda’s go-fast looking Honda CB550F Super Sport and ahead of Suzuki’s own GT550 2-stroke, which would be on showroom floors for one more year while Suzuki’s new middleweight 4-stroker established itself. All in all, the new Suzuki GS550 mill was a smooth performer, save for a pronounced buzz at engine speeds above 5,000rpm, unfortunately exactly where it produced the best power.

A single-disc front brake and drum rear were hardly exciting but were well paired and more than adequate to haul the 431- pound machine down to a stop in less than 125 feet, excellent performance for the day and still good today. The bike’s 6-speed gearbox, essentially a GS400 twin transmission and not a scaled-down GS750 box, as might be expected, was more than up to the task of transferring the 550’s power to the rear wheel, although some tAesters faulted its shifting quality, finding it notchy and with a pronounced false neutral between fifth and sixth gears.