Suzuki GSX250S Katana

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Suzuki GSX250S Katana
Manufacturer
Production 1991
Class Sportbike
Engine
Four stroke, transverse four cylinder, DOHC, 4 valves per cylinder
Compression ratio 12.5:1
Top Speed 174 km/h / 108 mph
Ignition Digital
Transmission 6 Speed, constant mesh
Frame Steel double pipe cradle
Suspension Front: 37 mm Telescopic forks
Rear: Swingarm, dual shocks, 4-way preload and 4-way rebound damping adjustable
Brakes Front: Single 300 mm disc, 2 piston caliper
Rear: Single 240 mm disc
Front Tire 110/70-H17
Rear Tire 140/70-H17
Wheelbase 1435 mm / 56.5 in
Seat Height 740 mm / 29.1 in
Weight 160 kg / 352 lbs (dry),
Recommended Oil Suzuki ECSTAR 10w40
Fuel Capacity 17 L / 4.5 US gal / 3.7 Imp gal
Manuals Service Manual


It could reach a top speed of 174 km/h / 108 mph.

Engine[edit | edit source]

The engine was a Liquid cooled cooled Four stroke, transverse four cylinder, DOHC, 4 valves per cylinder. The engine featured a 12.5:1 compression ratio.

Drive[edit | edit source]

Power was moderated via the Wet, multi-plate.

Chassis[edit | edit source]

It came with a 110/70-H17 front tire and a 140/70-H17 rear tire. Stopping was achieved via Single 300 mm disc, 2 piston caliper in the front and a Single 240 mm disc in the rear. The front suspension was a 37 mm Telescopic forks while the rear was equipped with a Swingarm, dual shocks, 4-way preload and 4-way rebound damping adjustable. The GSX250S Katana was fitted with a 17 L / 4.5 US gal / 3.7 Imp gal fuel tank. The bike weighed just 160 kg / 352 lbs. The wheelbase was 1435 mm / 56.5 in long.

Photos[edit | edit source]

Suzuki GSX250S Katana Suzuki GSX250S Katana Suzuki GSX250S Katana

Overview[edit | edit source]

Suzuki GSX 250S Katana











THE PASSING PUBLIC love the Kat. It's the style that moves them. The same style that was around a few years ago which nobody liked when it first came out. Fickle bunch, the public, but if they've created the incentive for Suzuki to recreate the Katana then I doff my hat to them. And who dares say the Katana isn't a thing of beauty? Obviously no-one, because they didn't pipe up when the Zephyrs were wheeled out, and they looked poncey, where the Kat is raw, has butch good looks from its sleek, three-spoke wheels to its aggressive bikini fairing. The four matt-black headers collect under the right footrest into a short, fat, black silencer. The radiator is hidden from view up under the yokes and the glycol tank tucks behind the airbox. It's all designed to look as air-cooled as possible. It's all very effective.

It's also like this Katana has been shrunk from the real thing — cunningly so. The fake fins fill out the frame and make the engine look wider. Next to an EXUP it's petite, of course, but we can't use that word again because it makes the Kat sound effete. There arc other bikes which are a bit twinky -those damnable Zephyrs again and the Yamaha Diversion. All much bigger capacity, you'll notice, but all failing to dish out the style like the Kat.

The Katana always looks large when you've parked it. You walk over and, oops-a-daisy, almost tripped over it. You thought it was five yards further on. Well, OK, you didn't, but you get what I mean. It's pretending to be bigger than it really is - a feeling that crops up often with the Kat. It feels quite weighty at a standstill; pushing the thing is quite tricky because you can't get your weight behind the low clip-ons. But stand astride it and you can rock the bike between your thighs. And then you realise how small it is.

The riding position's sit in/sit on. The long silver tank curves up under your chest bringing you close. Call it cramped, call it aggressive; but I'm calling it sporty. Switch on, lean for the bars, feel the weight taken by your wrists.

Thumb the starter. Roll the grip a quarter inch and feel the cough as one cylinder catches before the others. One quick wrist-flick settles the idle atjust over the thousand. Noise-check: the airbox whirred and the pipe whooshed. High tech electronic over base mechanical you might think. But you're wrong. Same old straight four as every other bike, just a bit smaller. Eight-day grandfather clock internals replaced by a self-winding Breitling.

Pulling away needs some clutch/throttle juggling to be smooth; 5000 revs keeps you ahead at the lights. But stick with that as your upper limit and you'll never see over 55kph which is fine for round town but tediously dull. Wring it and you'll double the torque available and drown out the measly whimper from the exhaust. And if you listen hard enough, you'll hear it say "...rev me, rev me..."

I was still in town, mincing around in top gear, so I had to wait. But even when I stomped down a few times the gearbox baulked, made a spranging sound and discovered a new neutral. This is a poor show from a box controlling only forty horses. Two stabs at one gear is more than a bimble down Main Street deserves. But once you've got the motor spinning over 7000 rpm the gremlins inside the box disappears and the shift improves hugely.

One thing that helps further are the ratios. Small engines are notoriously unrelaxing to keep on the boil, and only close ratios to keep in narrow power bands make any sense. The Kat's delicious selection could make sense of a menu at a Thai restaurant.

Take the engine to the red in any gear, shift up and you bang back to the bottom edge of the power band at eleven-five. A slight vibe through the right footpeg tells you it's time once again for forward motion, 4000rpm to play with before the next change and a sweet power curve in-between that makes the tacho needle fly. A*t first, the speedo needle moves like it's stuck in syrup compared to its banzai tacho neighbour. But suddenly there's 120 kph showing and from there to 140 is easy in top, faster in fifth and just right in fourth with an upchange.

Rolling around on the throttle at the top end of the dial is helped by powerful engine braking. Opening and closing the throttle without touching brake or gears is way more relaxed than 250cc should be. Assuming you find 14,000rpm relaxing.

When you listen to the Kat pull away you can't believe it can keep building revs. The first 7000rpm sound aircooled-noisy with tappet chatter. Ten thou's getting there: you can see folk tut-tutting with mechanical sympathy. Then the stocky silencer scream takes over from the mechanicals and the last 4000rpm provoke passers-by to hide behind trees and wait for the pistons to land. But what do they know? I must lay my hands on a CBR250. Apparently that revs to 22,000...

More surprising is that this same motor will happily pull away in top, with pillion, from just 2000rpm. Mr. Mikuni's clearly selling the right carbs for this bike; the four 29-mils fluff at five-five if you fist it, and maybe throttle response isn't totally sharp until the red's in sight, but that's nothing to pay for the ridiculous flexibility it gives.

Tootling in top from 3500rpm gives some kind of roll-on and eases noise, second gear's fine for pulling away. Clutch is as good as the gearbox is bad around town. Swings 'n' roundabouts.

Cradling the engine and propping up the 17in wheels is a silvery, tubular frame with unboltable lower rails. The suspension's Kayaba: twin shock back end and a steeply raked front with a reasonable 99mm trail. The relatively-long wheelbase claws back stability. Dry weight is 352lb; tubby for a 250 (the KR1-S is 289lb) but the Kat carries it well. Maybe that's why it feels so big.

Those geometry figures mean the Kat doesn't respond easily to knee nudges or when transferring weight through the pegs. This makes it feel a lot bigger than it is (again), but stop fooling around, give the bars a tweak and it turns very sweetly. A light, untroubling weave along the straights has been saying the steering could be fast; a slap or two down bumpy roads hinted at instability. But the Kat's just trying to wind you up. Once into a corner it'll bob 'n' weave a bit but essentially it tracks true with some spare handling for changing line or braking.

















Now try pushing it. This is a pretty subjective exercise because everyone gets their kicks at different levels, but I reckon anyone could ride the Kat and feel they've really found their limits - found their limits in an engine screaming, tire-sliding, tank-slapping, yeeeeec-HAW sort of way. Did I ever go round a corner thinking "no way could I take that any faster"? Nope, but it didn't matter a jot. My idea of pushing the Kat saw the suspension travel pretty much used up, gave the odd squeak from the tires, saw the front go a bit washy and felt the back slither. Now if that isn't Boy's Own hero material I'll burst into tears. And I didn't even, for the shortest pico-second, think I was going to fall off.


The early '80s bugbears of tires and brakes are the biggest get-away-with-it factors, with top billing going to the tires. Those Exedras can't be gripping extremely hard but they break so gently it's almost a pleasure. Where they really make friends is by complementing/totally upstaging the suspension which does its damnedest to keep the Bridgestones clear of the tarmac. Since air and rubber have a very low coefficient of friction it's remarkable that the Kat stays on line without leaping and squealing more than it does. What's more, a passing monsoon also confirmed they work well in the wet. And as the Kat isn't over-endowed with power, you'll be able to treasure each pair for years before wearing them out. 1500 miles left barely a scratch.

And the brakes. Two-fingered poetry. Tug the lever gently and the twin pistons whirr sexily across the big drilled disc. Now pick a speed. How many tires would you like howled today, sir? Just the one? Or perhaps both, with sequential locking to leave delicately-spaced black dots down the road. The front out-performs the forks and tires enough to set the stops jabbering and the tire chirping. Looks impressive? Feels dangerous? Every time. But don't be fooled. Ease the lever pressure, tip in and zoom.

Which is where I get a bit confused. The forks and shocks are clearly set up for the Japs which leaves them spectacularly under-cverythinged for chubby Britishers.

So why isn't the Kat more disturbed by silly behaviour like braking mid-bend? I started writing about four reasons but lost conviction halfway through each. Oh go on then, here are a couple: (a) Because the ccntre-of-gravity's so low, the weight of a fat blot perched high up holds the bike down and whatever tilting force is generated by the brakes isn't strong enough to overcome this, (b) Quite a lot of bikes don't stand up on the brakes anyway, so why am I getting all worked up? (c)... Er, no, I think I'll shut up. So much for Physics A-level.

Ahem, sorry about that. Shall we discuss the practicalities?


The seat hurts after an hour. Depends on bum shape, but there are two little prongs of bone at the rear of the pelvis which the Kat delights in baiting. Otherwise, long journeys are fine, the mirrors are clear and just wide enough, the wind takes the weight off your wrists, there's no vibration and the tank range is OK.

In fact, tank range is amazing if you don't realise the odometer records kilometers. Seven quid and 240 miles soon turns into 140 miles when you run out in Dudley instead of Chester which also equates to under 50mpg. Not so good for a small motor, but then it is being revved hard 90 per cent of the time and I see the ZZ-R250 only records 43 mpg with a far more efficient fairing. So there.

After a week of revving, the oil window had dropped from full to just above low.

Bedding-in could account for most of that. The only other slur worth casting upon the mechanicals is to mention the thrubble-bubble noise on the overrun.

The same week saw a more marked deterioration of the finish. The silver paint, lustrous in the extreme, looks a little prone to wear. An uncaring chap's zip had already drawn primer with only a light scratch, so an unpleasing tankpad might be the only remedy. The central header pipes took on a veneer of rust after the first shower, which also saw the brake light pack up. Strangely, the next dose of rain brought it back to life, one of those pieces of good fortune you don't question, so I won't. The tool kit was perfectly capable of whipping half the bike to pieces and that, pretty much, is that.

The only thing I haven't mentioned is that you can't officially get hold of a 250 Katana in Britain. This one came from Bat Motorcycles in South London who deal with all the bikes the importers are too shortsighted to include on their- lists. The pros and cons of grey imports were chewed over in the May issue, but what didn't come out was the feeling of riding something exclusive. There are only two Katana 250s in the country so far, and the other isn't registered. It's not as though the shape hasn't been seen before, but a Katana is individual enough to warrant a second glance from most. And if they know about bikes they realise everything's not quite as it seems; a J registration on a Katana which sounds like a 1960s 250 racer? And then they start to grin because they know you're on something a bit different and special, and you know that too and grin back. It's what bikes are for.


Source Bike 1992

















Make Model Suzuki GSX 250S Katana
Year 1991
Engine Type Four stroke, transverse four cylinder, DOHC, 4 valves per cylinder
Displacement 249 cc / 15.2 cu in
Bore X Stroke 49 x 33 mm
Compression 12.5:1
Cooling System Liquid cooled
Lubrication System Wet sump
Induction 2 x Mikuni 29 mm carburetors
Ignition Digital
Starting Electric
Max Power 29.8 kW / 40 hp @ 13500 rpm
Max Torque 26.4 Nm / 2.7 kgf-m / 19.5 ft-lb @ 10000
Frame Steel double pipe cradle
Clutch Wet, multi-plate
Transmission 6 Speed, constant mesh
Final Drive Chain
Primary Reduction 2.285:1
Final Reduction 3.769:1
Gear Ratios 1st 3.083 / 2nd 2.200 / .3th 1.722 / 4th 1.450 / 5th 1.285 / 6th 1.150:1
Front Suspension 37 mm Telescopic forks
Rear Suspension Swingarm, dual shocks, 4-way preload and 4-way rebound damping adjustable
Front Brakes Single 300 mm disc, 2 piston caliper
Rear Brakes Single 240 mm disc
Front Tire 110/70-H17
Rear Tire 140/70-H17
Rake 25.6°
Trail 99 mm / 3.9 in
Dimensions Length: 2060 mm / 81.1 in Width: 685 mm / 27.0 in Height: 1160 mm / 45.7 in
Wheelbase 1435 mm / 56.5 in
Ground Clearance3 165 mm / 6.5 in
Seat Height 740 mm / 29.1 in
Dry Weight 160 kg / 352 lbs
Fuel Capacity 17 L / 4.5 US gal / 3.7 Imp gal
Consumption Average 5.1 L/100 km / 19.6 km/l / 46.0 US mpg / 55.2 Imp mpg
Standing ¼ Mile 14.5 sec
Top Speed 174 km/h / 108 mph