Ton-up temptation
Contents
1. For best on road handling fit matched tyres 3 00 x 18 front 3 50 x 18 rear no bigger Over sized tyres affect stability Jetting is crucial to prevent holed pistons Standard main is 87 5 Without an airbox it s 105 With airbox but minus internal sponge try 97 5 jets Use genuine Suzuki pistons they have a high silicon content This gives greater durability Most pattern pistons look shiny because they re nearly all aluminium High silicon conten Maco hem que The ignition switch can wear and allow the key to come loose M amp P supply a pattern type Suzuki GP100 ignition switches fit too Check the brake light switch regularly It operates via the rear pedal only and the return spring can easily break I use semi synthetic oil It s cheaper than fully synth keeps the silencers clean and cuts down on smoke haze Many X7s have been tuned Some more than a little Ifthe clutch can t hold the power fit stronger springs or an extra steel plate The extra plate gives a more powerful clutch without making the lever too heavy If the original seat cover hasn t torn you have the only one Attend to it quickly or water will get in rusting the seat base all the faster When stripping an engine you only usually need to replace the outer seals Replacing the immer requires ihe crank to be pressed apart Be wary of pattern gaskets Some packs have extra thick head gaskets which reduce compression Gea2. Ton up temptation Suzuki s X7 was the first out of the crate 250 to be radar timed at 100mph 30 years on it s fast becoming THE air cooled 250 classic Dossier by Brian Crichton Pictures Mark Manning SPECIFICATION ENGINE TRANSMISSION Type air cooled parallel two stroke twin Capacity 241cc Bore x stroke 54 x 54mm Compression ratio 6 Z 1 Carburation 2 x 26mm Mikuni Primary final drive gear chain Clutch gearbox wet multiplate six speed Electrics 12v PEI electronic ignition CHASSIS Frame tubular steel single downtube frame Front suspension telescopic forks Rear suspension swingarm twin shocks 1x 10in disc with single pot caliper l x Zin drum Brakes front rear Wheels five spoke cast alloy Tyres front rear 3 00 x 18 3 50 x 18 DIMENSIONS Dry weight 2821bs 128kg Wheelbase 51 6in 1310mm Seat height 30in 762mm Fuel capacity 3 3 gals 14 8 litres PERFORMANCE Top speed 101mph Max power 28 5bhp 8300rpm Fuel consumption 35mpg Price new 763 MCM Aug 1978 uzuki s GT250 X7 was the first 250 to be radar timed at a genuine 100mph Back in 1978 the X7 s ton up credentials made it the most desirable quarter litre sports bike on the market And if the bike s performance was not enough to guarantee it s popularity Suzuki put it all together in a snazzily styled package which in its day looked ultra sporty Kawasa
3. ton His reward was 99 34mph A 1978 Would it really crack the genuine ton Suzuki wouldn t be drawn preferring to state top speed was around 100mph lt 1980 MCM s 118 7mph X7 on display It featured as part ofa shoot out tuning series against a 1977 RD250 that did 112 64mph gt 1978 Barbara makes light work of modelling the essential X7 accessory a Team Heron Suzuki jacket PERIOD ROAD TESTS The X weighs an astonishin 26alb dry 40b lighter than the bike t repla ces MCM Rug 197 ae I Not since the passing of the long lamented Super Six have Suzuki built a 250 which has stood head and shoulders above its competitors Now Suzuki are back in the hunt with their X7 model a sporting 250 if ever there was one with its claimed top speed of 100mph and styling to match The Suzuki looks considerably smaller than other 250s but this can t all be put down to clever styling for there is a lot less of it In fact the XT weighs in at an astonishing 2821b dry exactly 401b lighter than the bike it replaces It is able to match machines in the 400cc class Colin Mayo At I9 54mph the GT250 Is the fastest 250 MCN has tested MCN April 1978 On our test track the fantastic red devil of a bike went through the speed trap just one thousandth of a second outside a 100mph time With another 100 yards of track the first ton would have been easily
4. Barry Sheene was Suzuki s star turn lending a cheeky smile and a dash of charm Note the pre production bike s GT250 side panel stickers Production bikes had X7 badges I OWNED ONE sue Maddex 50 I bought my X7 new in 1979 when I was 242 and have had it ever since still have the HP agreement The bikes ofthe DeVemiles scemed really exciting Mie Xf was my first big bike I hadn t passed my test when I bought it Initially I was scared of the performance The acceleration was fantastic I couldn t believe it I still think ite an amazing machine I m now working to get it back on the road In fact I can t Even after 27 years Sue can t wait to ride it again wait to ride her X7 58 SEPTEMBER 2006 Classic Bike A 1982 York raceway Dave Walker works on Badger s right modified X7 The Micron which recorded 13 25s 101mph over the SS quarter using 271cc barrels Using this bike and another modified 250cc X7 Sidewinder 1 Brian took five ACU Elvington Pro street records four 250 one 350 The fastest one way speed he recorded was 118 7mph Brian still owns The Micron Anyone know what happened to Sidewinder I CNV 495T A 1980 Ifyour X7 s got the shakes it is probably on over sized tyres or as in this case on Suzuki s 1980 range brochure YV 1978 MCN s Paul Fowler buries his head in the X7 s clocks and makes himself as small as possible in an attempt to crack the magical
5. Don t be afraid to run different main jets in each cylinder eg a 90 in one and 87 5 in the other One cylinder can run a touch hotter than the other But deviating more than one or two sizes means there s something wrong FURTHER INFO e y Gr CONTACTS Suzuki GB 01293 766000 econmasaded plug yee NGK B8ES B9ES B10E UK suzuki importers Plug gap 0 6 0 8mm Crooks Suzuki 01229 822342 822120 Ignition timing 20deg BTDC 6000rpm Suzuki spares specialists Gearbox oil volume type 800cc SAE 20W40 I A B Fork oil volume type 154cc 10W20 Spares Direct 0208 969 0741 CU RHEE Bt del DOW Ieee Tiaras Ibit London based Suzuki spares stockists Clutch sleeve hub nut torque 29 43 51b ft Oversize stages 0 5 1 1 5 2mm Head bearing type ball and race Tyre pressures front rear 2lpsi 25psi Headlamp bulb 12v 35 35w Projected crankshaft life 20 000 miles Projected piston life Projected piston ring life Min clutch plate thickness Recommended chain play Straightline Racing 01553 811855 Tuning spares and parts specialists Slinger Motorcycles 01772 727213 Offical Suzuki dealer and parts stockists 15 000 miles 10 000 miles CLUBS 2 6mm Suzuki X7 Owners Club 15 20mm Sue Maddex 0115 953 2469 Min brake pad thickness marked by red line on pad Carburettor float height 25mm Standard main jet 87 5 Standard needle position 3 Air
6. ber Ian has tried riding through the wobble but couldn t and has deduced that skinnier tyres are the answer On the plus side the modern rubber makes this X7 feel very secure and progressive through corners at sub weave speeds It also has excellent brakes Better than original Ian has sensibly fitted braided hose to the front disc EBC green pads and has had a piston made from stainless steel to replace the corroded original It is far more effective than it was when new He has also modified the rear drum brake cam to give improved actuation It too is more effective that original Fun to ride and capable of dealing with modern traffic so long as you have the right jetting the X7 is Suzuki s last hurrah in terms of air cooled quarter litre strokers and it closed that chapter of Suzuki s history on a real high No wonder this flighty little twin is enjoying a renaissance nearly 30 years on 1978 1982 241cc Air cooled Parallel twin 100 2250 RIDING gt gt DEVELOPMENT gt gt NOSTALGIA gt gt BUYING gt gt OWNING 66Bear in mund that the edo reads fast To do a E a You can just see the blue haze that accompanies the X7 when given full bore f EE This shining white E S example was restored SS SS by owner Ian Finch J AAE _ S 3 LL a 5 a _ i A 1978 Suzuki unveiled the X7 to UK dealers at a glitzy reception at the Carlton Towers Hotel London
7. dn t all do it back then despite the hype No two X7s ever seemed to perform exactly the same Or feel the same The seat height on Ian s bike feels higher than I remember the steering lock seems more restrictive and when on the go this X7 feels undergeared The seat height is explained by the rear shock absorbers which are longer pattern replacements for an unknown model The tighter lock is due to the fact that Ian has fitted lock stop extensions to prevent the headlight struts touching the fuel tank on full lock And the gearing Ian says that it s standard so I put the difference in feel down to my failing memory Or could it be that this rebored engine is a very good example Pd like to think so X7s can feel quite flighty when ridden to the limit but riding this example at sensible speeds I was surprised at how nicely it steered holding a steady line through corners accompanied by an urgent crisp two stroke exhaust note through its stylish silencers X7s are tyre sensitive Ian s bike which looks marvellous in white is fitted with mismatched rubber and an incorrectly sized rear Continental City 3 00 front Avon AM21 110 80 18 rear and it doesn t like them It can get into a real dance from an indicated 75mph So much so that I didn t try to ride through the wobble I ve ridden tuned X7s at almost 120mph and know that though nervous in a straight line at speed they will hold a line when fitted with suitable rub
8. filter life 3000m 2 years SUZUKI GT SUPPLIES www suzuki gt co uk Front wheel bearings pair Rear wheel bearings pair 7 78 Seat seat cover 131 50 17 28 Clutch cable OE 15 25 Gearshaft seal OE 1 48 Exhaust downpipe OE 44 Fork dust seal 3 60 Swinging arm bearing OE pair 11 50 GRAMPIAN MOTORS Crank rebuild inc rods 0151 931 5009 up to 124 99 Piston kit OE pattern 27 20 15 22 Piston rings OE pattern 9 00 4 41 Gasket top end full pattern 7 35 10 50 Clutch plates friction x 6 OE 18 90 Crank seals outer pair 8 75 62 SEPTEMBER 2006 Classic Bike Email sue maddex ntlworld com Suzuki Owners Club Dave Gray 01480 387880 Email membership suzuki club co uk Vintage Japanese Motorcycle Club Anne Beer 01324 410519 Email membership_vjmc yahoo co uk USEFUL BOOKS Suzuki GT250X7 GT200 X5 amp SB200 Workshop manual By Haynes Publishing ISBN 0 85696 469 7 Suzuki GT250X7 Service Manual Factory manual Part number 99500 1210 OIE Price 30 50 WEBSITES www suzukisimon co uk www suzuki x7 org uk www suzuki gt co uk www suzukiownersclub co uk MISSED A DOSSIER Hesketh V1000 Morini 31 2 Sport Yamaha XT500 Triumph pre unit 650 twins Kawasaki GPZ900R Indian Enfield Bullet Silk 700S Moto Guzzi V7 Yamaha RD400 Suzuki Katana Ducati 750GT Sport BSA Bantams Ho
9. ins or a rusted piston Replacing the OE hose with a braided hose improves braking power FORKS Check that the drain screw threads in the bottom of the sliders have not been stripped The chromed stanchions corrode easily and pit if not cared for tearing seals as a result l ENGINE The engine should start readily and rev willingly Get a test ride XY engines usually need a rebuild at least every 20 000 miles if used hard Budget around 250 for a rebuild j i j k Cal i L s TANK Rusts internally and externally and can split at the seams Use Petseal to stop leaks Fuel taps can seize if unused Check that the filler cap lock hasn t been damaged 1978 1982 24icc Air cooled Parallel twin 100 2250 RIDING gt gt DEVELOPMENT gt gt NOSTALGIA gt gt l PAINT FINISH Steel and chrome parts are susceptible to rust Inspect the frame carefully to make sure it and the swinging arm are not weakened by corrosion SWINGING ARM The swing arm pivots on needle roller bearings which can rust and seize Check for sideways play Be prepared to fit replacement bearings At 12 a pair they re not too expensive gt gt OWNING Pat Daly X Racing Northtfleet Kent 01414 45252 If the engine won t run fit new plugs NGK B8ES for normal riding B9ES for hard riding B10EV for racing If it still won t start check for blocked exhausts
10. ki s KH250 and Yamaha s RD250 looked dated next to the dazzling X7 In the late Seventies being the fastest and best looking quarter litre machine mattered because impressionable 17 year old UK learners were allowed to ride bikes of up to 250cc No wonder X7s were strong sellers The new model was the first Suzuki road bike to feature a dual intake system piston port and reed valve and electronic ignition And it was the first Uk bound Suzuki to use cast alloy wheels Riding an X7 back then was a thrill especially for those on L plates Now 30 years on this compact twin has lost none of its appeal The bike s combination of light weight 282lb dry compact dimensions and crisp two stroke performance is perfect for tickling one s adrenal glands into action Acceleration is strong especially in the lower gears and its midrange performance is much healthier than that of the X7 s predecessor the GT250C which was very peaky Even so the X7 needs at least 5500rpm before it wants to get a move on as I rediscover 54 SEPTEMBER 2006 Classic Bike aboard Ian Finch s restored 78 machine It will rev beyond its 8500rpm redline in the lower gears but the sixth ratio is almost an overdrive you need favourable conditions to redline it in top When riding an X7 you have to bear in mind that the speedometer reads fast To be doing a genuine 100mph you need to see 110mph on the dial And they won t all do it now and di
11. nda CB400 Four BSA Road Rocket Laverda Jota Triumph Daytona Kawasaki Zl BSA Singles Ducati Singles AMC Twins BSA A65 Triumph T140 Yamaha RD350LC Suzuki GT750 Norton Dominator LC Honda CB750 Triumph Trident Dossier Reprints 3 each UK and EU 4 non EU Payment by cheque only Send to usual address on p98 4 50 per issue UK 6 EU 7 25 non EU Contact The Magazine Man tel fax 01270 878080 www themagazineman co uk back classic bike htm
12. possible But even at 99 34mph the GT250 is the fastest 250 MCN has tested and on acceleration it was nearly half a second quicker over a standing quarter than its granddaddy the GT250A It went through the traps in 14 76 seconds over a second faster than its nearest rival Yamaha s RD250 Paul Fowler ae Classic Bike SEPTEMBER 2006 S9 SUZUKI GT250 X7 concours 1800 2250 GOOD 650 1500 RATTY 250 450 BASKET CASE 100 250 ENGINE FRAME _ Note that X7 engine and frame numbers do not match Years given are approximate The frame number is on the headstock on Ce Phe ecngme number is on the nearside crankcase top behind the cylinder Numbers run from 1978 GT250N frame GT2502 10001 1979 GT250EN frame GT2502 500001 1980 GT250X frame GT2502 115097 1981 GT250EX frame GT2502 519409 Is IT DODGY Walk away when You intend to restore to original but are faced witha box of bits that doesn t include original exhausts airbox tank seat and front mudguard It could become an expensive proposition The runner you are contemplating doesn t have a log book won t pull the skin off a rice pudding or rattles and rumbles that s a total engine rebuild on the cards Your effort would be better spent finding a better example 60 SEPTEMBER 2006 Classic Bike DISC BRAKE Efficiency of the front sliding type caliper is compromised by rusty and worn p
13. r lever oil seals can go hard over time and cause gearbox oil leaks Classic Bike SEPTEMBER 2006 61 1978 1982 247cc Air cooled Parallel twin 100 2250 RIDING gt gt DEVELOPMENT gt gt NOSTALGIA gt gt BUYING gt gt Owners tips REPKO LAP Holland Owns 1979 GT250EN Use Castrol Super TT oil and fit a quality seat cover The original tears My model is Dutch spec with a different headlight and different carb settings so when ordering parts make sure the appropriate microfiche is being used IAN FINCH Lincolnshire Owns 1978 GT250N Use eBay to scour the world for parts If you want your X7 to continue to look good use stainless steel fasteners and spacers I spent more than 300 on them when I was restoring mine NEIL HORGAN Lancashire Owns 1979 GT250EN Get a manual the Haynes manual is good the factory manual is even better and service it yourself Xs are simple to work on For engine rebuilds I use Grampian Motors for parts I use a Metzeler MES3 front tyre and an Avon AMal rear STUART ATTRILL Northamptonshire Owns 1981 GT250EX If the engine starts well from cold and revs up cleanly thatis a good sign Be wary of examples that have no air box and don t be taken in by appearances My X7 looked good but it quickly ended up in bits for a total engine rebuild and welding to the crankcase BRIAN CRICHTON Northamptonshire Owns 1978 GT250N
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