On the move: Suzuki GS 750

Posted on by admin

Menus

On the move: Suzuki GS 750
Jahn

On the move: Suzuki GS 750

A question of timing?

Content of

Two-stroke engines up to 750 cm³ with two and three cylinders have long been the trademark of Suzuki. That was to change fundamentally at the end of the 1970s.


Jahn

With the market launch of the four-cylinder, four-stroke GS 750, the year 1977 brought a decisive change in model policy for Suzuki. A year earlier, the entire range had consisted of two-stroke engines. The only exception: the RE 5 with a rotary engine. She had been in the program since 1972 and played an absolute outsider role. The irony of fate: when it was being developed, Suzuki had already tested forerunners of the GS 750, but the designers had decided in favor of the Wankel and against the four-cylinder. As the only one of the four big Japanese manufacturers, Suzuki still held up the two-stroke flag and relied on cultivated two and above all three cylinders up to 750 cm³. Even Yamaha had had a two-cylinder four-stroke engine in its range for a long time with the 650 XS models. But the time for the simple working principle with the three moving parts was slowly running out in Hamamatsu, too, and American emissions legislation did the rest.

Modern four-stroke multi-cylinder should fix it and stand up to the competition. Correspondingly, the design of the GS 750 failed. A four-cylinder with two overhead, chain-driven camshafts corresponded to the current state of the art, as did the two valves per cylinder. With a 65 mm bore and 56.4 mm stroke, the GS was considered a downright short-stroke engine at the time and, with the DOHC valve control, offered high speed reserves for a corresponding power output. But despite the elaborate construction, Suzuki held back with the power rating of 63 hp. Honda’s slightly long-stroke four-cylinder, the CB 750, has had an unchanged nominal output of 67 hp with an overhead camshaft since 1969.

And while the first model with spoked wheels still had a single disc brake in the front wheel when it was presented at IFMA 1976, Suzuki delivered the series with a double disc brake in spring 1977. Just one year later, cast wheels replaced the spoke wheels, and the GS 750 E was born. This is the model of Roland Kletti, the chairman of the Suzuki GS-Stammtisch Karlsruhe.
Today as then, the Suzuki GS 750 impresses with its clear, straightforward lines. The smooth tank-seat line, the four-in-two exhaust system with the slim, megaphone-shaped silencers and the simply drawn cast wheels make it a timelessly elegant classic.

At the start, briefly tried the choke, which was enthroned only for a short time in the middle of the central nut of the fork bridge, as with our model, and soon the four-in-line runs smoothly. The sitting position behind the flat, narrow handlebars is almost sporty, the handlebar ends are not bent back enough so that the wrists are angled too far outwards and smaller riders take a moderately sporty sitting position with the upper body slightly bent forward.

Engaged in first gear in the smooth-running gearbox, the GS starts moving rather unspectacularly. From 4500 to 6500 rpm, the torque curve shows a slight drop, but this is not particularly significant when driving. Above this, the engine climbs relatively evenly up to 9000 rpm thanks to its usable speed range. The sound is also moderate, completely lacking the hissing of the four-in-four systems of a Honda CB 750 or Kawasaki Z 900. Just a fine tingling sensation in the handlebar ends and footrests, typical of engines with a crankshaft with roller bearings, testifies to the existence of the engine. The gear indicator is a gag – the driver notices it, but doesn’t really need it.

More driving impressions

The chassis also deepens the impression of the problem-free companion. Undeterred and with a stable track, the GS pulls its course in bends with bumps and offers excellent handiness. She hardly knows pendulum phenomena. The lean angle is also beyond any doubt. The telescopic fork responds sensitively, and together with the rear suspension struts, the chassis is more comfortable. The damping alone could be tighter at the front and rear. Nevertheless, the GS 750 proved to be up to the competition in terms of driving behavior – a criterion that was still very important at the end of the 1970s. In the individual test in MOTORRAD 4/1977 tester Franz-Josef Schermer did not spare praise: "The responsible designers attached great importance to the coordination of the telescopic fork and spring struts. The rear swing arm was mounted in fine needle bearings. As a result, the GS 750 has a largely neutral driving behavior, runs reliably in a straight line and is extremely willing to turn. It does not waggle in long curves, and the pitching movements that are excited when driving over bumps in an inclined position subside without reverberation."

The double-disc brake system in the front wheel was convincing and clearly superior to the direct competition. With little manual force and easy to dose, it decelerated significantly more effectively than the single-disc systems from Honda CB 750 and Co. and still leaves a safe driving impression today.

The gears can easily be stepped through the easily switchable gearbox and snap into place cleanly. All in all, as in the first test in MOTORRAD 4/1977, the Suzuki leaves the impression of perfection, the problem of which is that the overall impression is a bit non-binding, even ironed out. An impression that Tetster Schermer also gained at the time. He called the Suzuki an honest man, if not in a negative sense. His credo: "The GS 750 impresses more with its solidity than with its extraordinary technical solutions." Whereby, then and now, their inconspicuous behavior makes them easily underestimated.

This fact was also reflected in the first comparative test on the Nurburgring’s Nordschleife. For the evaluation, MOTORRAD used concise sections of the route: "Not to test the candidates for their suitability for racing, but to find out condensed statements about suitability for everyday use. MOTORRAD chooses Ring and Hatzenbach because all extreme situations occur there that the driver encounters in small doses every day."

In the relentless test of strength with the BMW R 80/7 S, Honda CB 750 F2, Kawasaki Z 650 and Yamaha XS 750, the Suzuki GS 750 pulled out of the affair with flying colors and landed its first victory, albeit just ahead of the Kawasaki. Above all in the chassis criterion, the GS 750 got top marks for straight-line stability, cornering ability, cornering safety and front brake with a maximum of 10 points, and it also showed the competition the rear light in terms of performance. In the acceleration from 0 to 100 km / h in 4.5 seconds, it clearly outperformed the second fastest, the Honda, and was also just ahead of the nominally nine hp Honda with top speed of 198 km / h. But the lap times on the Nordschleife were far more meaningful.

With the best time of 10:45 minutes, the GS 750 clearly relegated the competition to its place. The Kawasaki was five seconds behind, the Honda even lost ten. This enabled the Suzuki to emphatically demonstrate its potential, even if the testers had not expected it thanks to its balance. And the conclusion of this test was in the same way: "All in all, the Suzuki was the most balanced, the fastest and the most powerful in this group test. Your diligent collecting of points brought the overall victory."

The chassis clearly showed itself to be able to cope with the engine power at all times, a criterion that was by no means always met at the time. The positive assessment can still be easily understood today. But the competition did not sleep. Engine and chassis development has seldom progressed faster than at the end of the 1970s, and so the Suzuki GS 750 was only able to demonstrate its undeniable qualities for a short time. The market launch of the GSX 750, now with four valves per cylinder, ended the Suzuki four-cylinder two-valve era in 1980 after a few years.

Technical specifications


Jahn

Suzuki GS 750

Engine: Air-cooled four-cylinder four-stroke in-line engine, two valves per cylinder, two overhead chain-driven camshafts, bucket tappets; Bore 65 mm, stroke 56.4 mm, displacement 749 cm³, compression 8.7: 1, 63 hp at 8800 / min, 52 Nm at 8100 / min, mixture preparation: Mikuni round slide carburetor, 26 mm

Electrical system: E-starter, battery: 12 V / 14 Ah, battery / coil ignition, contact-controlled, alternating current generator, 200 W.

Power transmission: Multi-disc oil bath clutch, claw-shift five-speed gearbox, primary drive: gear wheels, secondary drive, O-ring chain

Landing gear: Double loop frame made of tubular steel, front telescopic fork, ø 35 mm, rear double-arm swing arm with two suspension struts, cast wheels, front tires: 3.25 H 19, rear tires: 4.00 H 18, front double disc brake, ø 275 mm, two-piston fixed calipers, rear disc brake, ø 275 mm, two-piston fixed caliper

Measurements and weight: Wheelbase 1490 mm, seat height 800 mm, weight 253 kg, tank capacity 18 liters

Driving performance: Top speed 198 km / h

Price: 6990 Mark (1978)

Manufacturer: Suzuki Motor Co. Ltd., Hamamatsu, Japan

Leave a Reply

Your email address will not be published. Required fields are marked *