Suzuki GS550 Parts & History

The Suzuki GS550 is a classic motorcycle that captured the hearts of riders with its blend of performance, reliability, and stylish design. Launched in June 1977 as part of Suzuki's new GS family of DOHC four-stroke machines, the GS550 quickly established an enviable reputation for its smooth performance and durability. This article delves into the history of the GS550, its technical specifications, and where you can source vital parts to keep this iconic machine running.

The Genesis of the Suzuki GS550

The Suzuki GS550 made its debut in 1977, marking a significant step for Suzuki in the burgeoning market of multi-cylinder roadsters. It was part of a new wave of Japanese motorcycles that were moving away from older traditions and embracing more modern engineering. The GS550 was a twin-cylinder variant within the GS family, alongside its four-cylinder siblings. Its air-cooled engine was a testament to sophisticated engineering, delivering a solid 49hp at 9000 rpm. The initial models, particularly the early GS550s from 1977 and 1978, are now highly sought after by collectors for their classic styling and are considered by many to be the most aesthetically pleasing of the GS Four series. These early models featured spoke wheels, which were updated in 1978 with cast wheels and improved braking systems, including twin front discs and a single rear disc.

Engine and Performance: A Closer Look

The Suzuki GS550EN, a variant of the standard GS550N, exemplifies the mainstream motorcycle design of the 1970s. Its transverse four-cylinder engine, equipped with four carburetors, dual-overhead camshafts, disc brakes, and cast wheels, represented the epitome of modern motorcycle technology for many riders at the time. While it incorporated some features that predated 1969, such as two valves per cylinder and a breaker-points ignition system, its overall design was state-of-the-art. The engine, displacing 549cc with a nearly square bore and stroke of 56.0 x 55.8 millimeters, was known for its willingness to rev. Suzuki engineers strategically employed roller bearings in several parts of the engine's bottom end to reduce the requirement for high engine oil pressure.

A unique characteristic of the GS550 engine is a noticeable high-frequency resonance that emerges just below 6000 rpm and continues to the redline. This vibration, while present, discourages prolonged high-rpm running, but the engine is exceptionally smooth and comfortable at lower RPMs, making it ideal for around-town cruising and shorter highway journeys. The GS550's powerplant needed high revs to produce its peak horsepower, which was around 41.55 hp at 8500 rpm. This made the six-speed transmission particularly useful for keeping the engine within its powerband, although the vibration could sometimes make exploiting this advantage a nuanced experience.

Engine Specifications Comparison

Chassis and Handling

Suzuki's GS series motorcycles are renowned for their robust and rigid chassis. The GS550's frame, constructed from mild steel tubing with 1.12-inch main members, featured a heavily gusseted steering head with a 29-degree rake and 4.72 inches of trail, contributing to excellent handling characteristics. The bike maintained composure at high speeds, with minimal frame flex and wobble. Its 56.5-inch wheelbase provided good straight-line stability, making it a capable touring machine. Around town, the GS550 was agile and easy to manoeuvre, a testament to its thoughtful design.

Suzuki also emphasized strength in the swingarm, using a mild steel tubular assembly with 1.5-inch outside-diameter arms. This robust construction contributed to the bike's overall weight, which was around 476 pounds when full of fuel. In terms of suspension, the GS550 utilized an oil-damped steel spring fork and oil-damped rear shock absorbers with five adjustable spring preload settings. While competent, the suspension was not as technologically advanced as some of Suzuki's higher-end models, but it offered a comfortable ride for most conditions.

Model Variants: GS550EN and GS550LN

Suzuki was adept at offering variants to cater to different rider preferences and market trends. The GS550EN, for instance, introduced cosmetic enhancements like cast wheels, a rear disc brake, and a stepped seat, offering a more customised look for a modest price increase over the standard GS550N. These 'E' models proved commercially successful, often outselling their standard counterparts.

Later, responding to the fashion for 'raked-out' styling, Suzuki introduced the GS550LN. This model featured a leading-axle fork with different spring rates and lighter rebound damping, along with less preload on the rear shocks for a softer ride. The LN also had a slightly longer wheelbase and reduced rake and trail compared to the EN. While these styling changes appealed to a segment of the market, some riders found the LN's riding position, particularly the high-rise handlebar, less comfortable for spirited riding, suggesting it was more suited for 'boulevard cruising'.

Where to Buy Suzuki GS550 Parts

Finding parts for classic motorcycles like the Suzuki GS550 is crucial for maintenance and restoration. Z1 Enterprises is highlighted as a leading destination for Suzuki GS550 motorcycle parts. They boast a large inventory of vintage motorcycle parts and offer same-day shipping within the continental US, ensuring that enthusiasts can find what they need to keep their bikes on the road.

Other reputable sources for classic Japanese motorcycle parts include:

• Old Bike Barn: Offers a wide selection of Suzuki GS550 parts, including engine gasket sets, carburetor kits, fork seals, levers, cables, and brake pads, essential for resurrecting and maintaining these machines.
• Specialty online retailers focusing on vintage Japanese motorcycle parts.
• Motorcycle forums and enthusiast communities where parts are often bought and sold privately.

Common Questions about the Suzuki GS550

What year did the Suzuki GS550 come out?

The Suzuki GS550 was launched in June 1977.

What kind of engine does a Suzuki GS550EN have?

The GS550EN features a 549cc, air-cooled, DOHC, inline-four-cylinder engine with dual overhead camshafts and four carburetors.

What is the best carburetor kit for a Suzuki GS550?

While specific recommendations can vary based on the exact model and condition, reputable brands like Mikuni are often favoured for their quality and performance. It's important to ensure the kit is compatible with your specific GS550 model year and any modifications. Checking with parts specialists like Z1 Enterprises or Old Bike Barn can provide guidance on the best available kits.

How much did a Suzuki GS550 cost originally?

The original Suzuki GS550 had a suggested retail price of $1,745.

What is the difference between the Suzuki GS550 and GS750?

The GS550 and GS750 were part of the same Suzuki GS family. The primary difference lies in their engine displacement and configuration: the GS550 typically featured a 549cc inline-four, while the GS750 had a larger 748cc inline-four engine. Both represented Suzuki's entry into the four-stroke, multi-cylinder motorcycle market, with the GS750 being the larger, more powerful sibling.

Conclusion

The Suzuki GS550 remains a beloved motorcycle, appreciated for its robust engineering, smooth performance, and classic styling. Whether you're a collector, a restorer, or simply a rider who appreciates a well-built machine, the GS550 offers a rewarding experience. With dedicated parts suppliers like Z1 Enterprises and Old Bike Barn, keeping this iconic Japanese motorcycle in excellent condition is more achievable than ever. The GS550 is a testament to Suzuki's engineering prowess in the golden era of motorcycle manufacturing.