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Suzuki GSX 750F Katana

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Make Model

Suzuki GSX 750SF Katana 

Year

1985 - 87

Engine

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

Capacity

747 cc / 45.5 cu-in
Bore x Stroke 67 x 53 mm
Cooling System Air cooled
Compression Ratio 9.4:1
Lubrication Wet sump
Oil Capacity 3.2 Litres / 3.4 US qt / 2.8 Imp qt

Induction

4 x 32 mm Mikuni RS32SS carburetors.

Ignition 

Transistorized 
Ignition Timing 15º BTDC below 1500 rpm / 35º BTDC above 2350 rpm
Spark Plug NGK D8EA (in E-01,24,25,30,34), NGK DR8ES-L (the others) - gap 0.6-0.7 mm (0.024-0.028 in)
Battery  12V 50.4 kC (14 Ah)/10HR - type YB14L-A2
Generator Three-phase A.C. generator
Starting Electric

Max Power

62.6 kW / 84 hp @ 9500 rpm

Max Torque

68 Nm / 6.93 kgf-m / 50.2 lb-ft @ 8500 rpm

Transmission

5 Speed constant mesh
Final Drive Chain
Primary Reduction 2.162:1 (93/43)
Final Reduction 2.733:1 (41/15)
Gear Ratio 1st 2.571 (36/14) / 2nd 1.777 (32/18) / 3th 1.380 (29/21) / 4th 1.125 (27/24) / 5th 0.961 (25/26)
Final Drive Chain Daido D.I.D 630V, 96 links
Frame Steel, double cradle

Front Suspension

Telescopic, preload adjustable and hydraulic anti-dive.
Front Wheel Travel 150 mm / 5.91 in

Rear Suspension

Dual shocks, 5-way preload and 4-way rebound damping adjustable.
Rear Wheel Travel 109 mm / 4.29 in

Front Brakes

2 x 275mm Discs, 2 piston calipers

Rear Brakes

Single 255 mm disc, 1 piston caliper

Front Tyre

3.25 H16

Rear Tyre

4.00 H17
Caster 61º30"
Rake 30°
Trail 116 mm / 4.67 in
Dimensions Length 2250 mm / 88.6 in
Width     715 mm / 28.1 in
Height  1195 mm / 47.0 in
Wheelbase 1520mm / 59.8 in.
Swat H eight 775 mm / 30.5 in
Ground Clearance 175mm / 6.9 in

Dry Weight

228 kg / 503 lbs

Fuel Capacity 

22 Litres / 5.8 US gal / 4.8 Imp gal

Standing ¼ Mile  

11.9 sec / 182 km/h / 113 mph

Top Speed

215 km/h 134 mph

Though outflashed by the new-wave hundred horsepower hotshots, Suzuki's 750 Katana is still a hell of a bike. A "brief, brisk" look at one of the most impressive four-cylinder sportsters around.

The Suzuki's 750 Katana appeared in Oz last year when the extensively redesigned bike made its appearance, almost three years after the debut of Ihe original version. Riders benefited from increased power, great weight reduction and improved comfort. The level of the '84 model's refinement was light years ahead of its predecessor and in this sphere the revised Kat was top of the tree in the 750 sportster class.

Not surprisingly, Suzuki has stuck with the winning formula and the "85 model is scarcely changed; in fact the revamp is entirely cosmetic, confined to paintwork, the addition of a fuel gauge, and finish. A rich grey replaces the "almost-white" of the '84 model and those whose sensitivities were offended by the liberal spreadings of gold will be heartened to hear that most has been discarded. The SF's frame is conservatively black, while the left and right engine cases and rocker cover have returned to the traditional polished alloy finish. The wheels and calipers are all that's left of Suzukis "golden" period. Also making a welcome disappearance are the fairing-mounted stickers which extolled the SF's sporting prowess — not a bad move either!

Aside from these alterations our bike was identical to the one we tested last November, so rather than rehash the revelations of the full test we'll make this one brisk, and brief.

As the Katana was, until recently, the top-line 750 from the Suzuki stable, the suspension, frame and motor still have a lot to offer.

No plunge!
The suspension system, certainly, is superbly efficient. Forks incorporate a system which varies compression damping according to the rate of fork movement and amount of travel, so over small bumps the forks react normally, but hit a big mutha and damping is increased over the latter half of the fork stroke. It's a good system in principle and performance, offering quick response over slight road irregularities and firmness when it's needed — over the rough. Forks don't carry antidive gear, which would be redundant anyhow since the variable damping unit does the job and is four-way adjustable. Spring preload can also be set lo any of four positions.

Rear suspension is also top-notch. Suzuki's Full-Floater set-ups have always been impressive and the Katana's is no exception. The smoth progressive action and beaut compliance do a great deal to encourage comfort and surefootedness. An easily accessible preload adjuster is a fine finishing touch.

Other sports-orientated features include the compulsory 16-inch front wheel which were considered gung-ho a few years back are now consigned tothe depths of normality. Much the same can be said of the frame, the only distinctive feature of which is that curious mix of box-section steel in the exposed areas and oval section elsewhere. Otherwise it's a pretty ordinary double cradle item which is not left wanting in strength or rigidity.

Like the frame, the motor wouldn't give the diehard high-tech hotshot much to shout about as it's basically quite similar to the original GSX750's engine. Admittedly the transition over the years has included a healthy bit of dieting and numerous changes to cams, valves, engine cases, carburettors and so on, but it's still an air-cooled in-line four with double overhead camshafts. Twin Swirl Combustion Chambers and tour valves per cylinder. Of course power output has grown over the years and the new Katana boasts 66.2 kW, a great improvement over the original version's 60.4 kW.

On the pace
This claimed maximum puts the GSX right among the top runners. It's 1.4 kW short of the Kawasaki GPz-R's peak and 0.8 kW less than the Honda CBX750-s maximum but lower gearing gives the Katana top-end fifth gear acceleration almost equal to the best — up to a point. However, Ihe Kat runs out of puff earlier and consequently its maximum speed of 205 knvh falls short of the CSX (220 knvh) and GPz (226 km'h). An academic distinction, though, since few riders ever run past 190 km/h and where it counts for more, in the midrange, the Suzuki is stronger than both.

If you expect that the 5.8 kW power difference between the old and new Katanas would lead to significantly improved performance then you'd be right. But there is one other important contributing factor to brisker acceleration — less weight. The new Katana is around 25 kg slimmer than of old and is the lightest 750 four available at present — apart from the just-released FZ Yamaha and GSX-R Suzuki. This characteristic is particularly noticeable when manoeuvring, riding at very low speed or pushing through a series of ultra-tight comers. The bike is so well behaved, light and low in the seat that you need the odd reminder that there are 750 cubes beneath the seat, not 600.

Other facets of the bike's handling are equally impressive. Steering is quick yet precise at all speeds. Only some low-speed self-steering removes it from the realms of perfection. Cornering clearance is more than ample, high-speed stability excellent and overall behaviour over smooth surfaces impeccable. Of course the 16-inch front wheel gremlins surface but happily the Katana is not severely affected. The bike isn't the best in this regard (the GPz-R is) but it's a shade better than the CBX750 and a whole lot less unsettling than some others such as the VF750. VF1000 and FJ1100. to name but a few.

8rakes are well up to the task of coping with the performance but the twin-piston fixed caliper system adopted by Suzuki in 1983 still doesn't provide sufficient feel.

Refinement has always been part of Suzuki's game and the Katana reflects this in many ways. The motor is basically buzz-free, the transmission is smooth while paintwork and finish are typically superb. The pop-up headlight is a bobby dazzler and comfort is above average by virtue of the good seat and compliant rear suspension.

Built for speed
Of course the Katana is a sportster, so the riding position is tailored to suit, and passengers will not be too happy about long periods in the saddle. But for solo work the Suzuki is very competent over long distances and good economy and reasonable fuel capacity ensures that touring range is more than respectable.

In its intended sphere of operation the Katana can fang it with the best. Steering precision and high-speed stability may not quite reach the exalted levels of the GPz but the Katana is almost as good and much easier to pilot in tight going where its low weight Is a telling factor.

Whether the bike is the best 750 around at present is a difficult one. The GSX is not the quickest or fastest and overall the handling, though excellent is degrees behind the GPz750R kWaka. But there's not much in it. and the Suzuki is almost S600 cheaper. In these inflation-ridden days, that's more than enough to move it close to the top of the class.

Dave Bourne 1985