.

Suzuki GSX-R 750

.  

Make Model

Suzuki GSX-R 750

Year

1991

Engine

Four stroke, transverse four cylinder, DOHC, 4 valves per cylinder.

Capacity

749 cc / 45.7 cub. in.

Bore x Stroke

70 x 48.7 mm

Compression Ratio

10.8:1

Cooling System

Air/Oil cooled

Engine Oil

10W/40

Exhaust System

4-into-2-into-1 Stainless-steel exhaust

Lubrication

Wet sump

Induction

4 x 38 mm Mikuni constant-vacuum carburetors

Ignition

Computer controlled electronic ignition

Spark Plug

NGK CR10EK

Starting

Electric

Max Power  

83.8 kW / 115 hp @ 11000 rpm

Max Power Rear Tyre

75.9 kW / 101.8 hp @ 11000 rpm

Max Torque

78 Nm / 7.9 kgf-m / 57.5 ft-lb @ 10000 rpm

Clutch

Cable operated, wet multiple, coil spring

Transmission

6 Speed, constant mesh
Final Drive #530 Chain, O-ring sealed, 108 links
Gear Ratios 1st 2.77 / 2nd 2.25 / 3rd 1.65 / 4th 1.40 / 5th 1.23 / 6th 1.09:1
Frame Lightweight aluminium alloy frame incorporated 45mm box tube main section and cast swing arm pivot

Front Suspension

41 mm Upside-down telescopic fork, adjustable spring preload, 8-way damping, 10-way compression

Rear Suspension

Full-floater Monoshock 4-way adjustable for preload rebound damping

Front Brakes

2 x 310 mm Discs, 4 piston calipers

Rear Brakes

Single 280 mm disc, 1 piston caliper

Wheels

Alloy, 3 spoke

Front Rim

3.5 x 17

Front Tyre

120/70 ZR17

Rear Rim

5.5 in x 17

Rear Tyre

170/60 ZR17
Wheelbase 1420 mm / 55.9 in.

Dimensions

Length  2070 mm / 81.5 in.

Width      730 mm / 28.7 in.

Height   1135 mm / 44.7 in.

Seat Height

790 mm / 31.1 in

Dry Weight 

208 kg / 459 lbs

Wet Weight 

249 kg / 549 lbs.

Fuel Capacity 

21 Litres / 5.5 US gal / 4.6 Imp gal

Average Consumption 

6.8 l/100 km / 14.8 km/l / 34.8 US mpg / 41.5 Imp mpg

Braking 100kmh - 0 / 60 mph - 0

36.5 m / 120 ft

Braking 60 kmh - 0 / 37 mph - 0

13.8 m / 45.3 ft

Standing ¼ mile

10.88 sec / 201.7 km/h / 125.3 mph

Top Speed

247.3 km/h / 153.6 mph

Colours

White/Blue

The 1991-year's GSX-R750M weighed 15 kg more than the previous model! Some Suzuki sales brochures didn't even bother to quote a weight figure. The weight factor alone sends this bike to the back of the GSX-R pack. New aerodynamic fairing with slanted nose to reduce frontal drag, with distinctive headlight cover and running lights. The seat was enlarged and twin tail lamp design graced the backend. The oil-cooled SACS engine received internal refinement of adopting one rocker arm per valve from the previous of one per two valves, stronger valve springs and an exhaust cam with 7 degrees less duration to give 116 hp.

GSX-R 750l History 1988-1991

In addition to SACS and Hyper Sports, this Suzuki GSX-R also had ‘Slingshot’ emblazoned on its flanks. This came from the bike’s redesigned Mikuni carburetors, which had straighter intakes for better combustion efficiency. This GSX-R, with its then radical, all-new styling, looked menacing. Mess with it and it would kill you.

Power was up to a real world 92 horsepower and the bike was capable of doing more than 230km/h in a straight line. The new, shorter stroke 749cc inline-four got a new bottom end (adapted from Suzuki’s own GSX-R1100), revved quicker and higher than the old model’s engine and was less peaky. While the older GSX-R didn’t wake up at all before 7,000 revs, the new one started making its grunt from 5,000rpm onwards – a big improvement for low speed, city riding. In a surprise move though, the M model went back to a longer stroke engine (perhaps to improve rideability and further reduce peakiness…?), which also made a genuine 100bhp for the first time.

The bike’s chassis was a strengthened, beefed-up version of the first GSX-R’s perimeter alloy frame, and steering geometry was made more radical in order to quicken the steering. The M version was the first production motorcycle to get upside-down (USD) front forks, which are now almost ubiquitous on all sports machinery. The ‘Slingshot’ GSX-R also got wider wheels, stickier rubber and higher-spec, multi-adjustable suspension – all of which helped in making it a better tool for the racetrack, where a lot of these bikes ended up being used. With its near unburstable engine and its proclivity for wheelies, stoppies and other acts of assorted two-wheeled hooliganism, this was a ‘proper’ Gixxer and a worthy successor to the first bike.

Review

by Trevor Franklin

It was on the exit to a second gear corner on my way home from the office. It was dark, and the reasonably adequate twin idlights were picking out the black, asy surface as they had done several times already.

But there was something strange about way the bike was responding to an enusiastic fistful of throttle. The back of bike felt soft and the bars were just beginning to edge toward opposite lock. Finding rather less friction than usual the rear Michelin had started to slew sideways until, after 30 or 40 yards, it must have been two or three inches out.

The sudden dawning of realisation snapped the throttle shut and with barely a quiver the bike snicked back into line. All a complete accident, of course, but it illustrates exactly the GSX-R's flawless engine and chassis response. Even with minimal protection of jeans and a leather jacket I hadn't felt frightened or relieved; just impressed.

The 750L can't help being impressive. It sets new standards for power in its class, has the finest suspension of any production roadbike, carburates impeccably and will smoke a quarter in 10.89 seconds, making it the first 750 to get inside the elevens. Within the constraints of its design brief and price it's pretty close to ideal. Add a little more torque, higher gearing and a V4 exhaust note and it could be an RC30. It wheelies over bumps like one. Yum yum yum.

The philosophy is basic GSX-R (light, powerful motor, racing steering geometry and the widest tyres current technology will permit) with a refinement: soft, soft springing, front and rear, backed up by very high quality damping. The advantages are ride comfort and the highest possible degree of wheel control, tuneable to any conditions. The disadvantages are that it's all very confusing; it interacts subtly. Even a passer-by fiddling with the SUZUKI rear compression damping knob will upset the rider, and working out what's wrong is another matter.

In fact, unlike the 1100, the 750's stock settings are very good but because you, the rider, have all that adjustment, you end up desperately wondering if you've got it right instead of just riding the thing. I felt in constant fear of a man in an Ohlins van pulling up alongside me at the lights: "Hah! What are ya? Rear rebound on position three? Yer wanker." Etc, etc. Fortunately this never happened.

Riding the GSX-R on the open road is a world of minimal effort, almost a state of grace. For a start, it makes the 1100 feel like a tank. You can place the 750 exactly where you want with time to spare, flick it into bends with opposite body lean like Kevin Schwantz, climb off it for a right-hander while the bike's still exiting the previous left. One finger pressure on the bars — I tried this — is enough to guide the bike accurately through a 90mph corner. It's not just smooth progress; the bike and rider seem to flow over the countryside, egged on by a delicious sense of relaxation at speed. The frame and engine seem semi-independent of the road surface — only occasionally does a major shock get through.

This is the Suzuki at its best. Nothing can match the isolation of the unsprung mass from road shocks. The motor revs so incredibly smoothly, the motion of the suspension is so refined, the gliding sensation so complete... it's as if every bearing in the engine, wheels, chain and Full Floater linkage is working at the peak of perfection, greased by the finest grease in the world. The whole bike is a study in chassis excellence.

The motor suits this character perfectly. Apart from the sheer brute force of 95bhp (125mph in under 11 seconds and all that) it's the smoothness and evenness which impresses. It needs choke first thing in the morning but you can knock it off straight away and get a clean-running, driveable motor which ticks over evenly. When it's warm it'll take 25mph in top, the well-damped response from the 38mm CV Slingshots permitting snatch-free acceleration at any revs in any gear. Transmission slop is absent.
Power builds so smoothly that the sensation of acceleration is disguised compared with the slower but gruntier VFR. It takes a speedo check to realise how fast the GSX-R is travelling sometimes. If you really go looking for it the motor goes a bit dead between 5,000 and 8,000, pulling strongly below these revs and... very strongly above.

The killer action is between 10,000 and 12,000. The large tarantula in the ointment is fuel consumption. The GSX-R guzzles gas so greedily that its vast, 5.5 gallon fuel supply disappears into the atmosphere before you can believe. Solo (open, dry) road use gave around 33mpg and a range of 150 miles (including nibbling into reserve). The best figure I got, 38mpg, was during the enforced restraint of pillion carrying. Riding the bike round town for those vital urban fuel figures was so bloody awful I didn't bother.

Meanwhile, the pillion: detailed comment was unavailable due to an abundance of four-lettered expletives. The footrests are too high, the seat is slippery, there's no grab rail, the passenger's head sticks up into the airstream and all his/her weight is taken through the coccyx. Apart from that it was luxury. For the rider, the extra weight and responsibility completely kill the bike's fast-turning, hard-braking ability. You have to ride the bike so gingerly that the wrist-heavy riding position starts hurting within ten miles, whereas solo is good for 200. If you're planning lots of two-up riding, slow riding, or both, buy something else.

In day to day use the Suzuki coped reasonably. A tiny magnetic tankbag will just about fit but carrying luggage on the back isn't really possible if you value your paintwork, and the stooped riding position rules out a rucksack if you value the blood circulation in your arms. The steering damper isn't noticeable at low speed, but with suspension this good stability isn't a problem anyway. Still, it's nice to know that if you want to ride like an idiot you can get away with it.

After two weeks I came to the conclusion that the GSX-R is too delicate a creation for real life. I could already feel road grit in the damping adjusters. If it were mine, I'd have simply refused to ride it in the rain. All that bare alloy — it'd be a crime to use the bike at all in winter. An astonishing bike to ride, but make sure you understand its limitations before you buy one.