Suzuki GS425E

Suzuki GS425E
Manufacturer	Suzuki
Production	1979
Class	Standard
Engine	Four stroke, parallel twin cylinder, DOHC, 2 valves per cylinder.
Compression ratio	9.1:1
Transmission	6 Speed
Suspension	Front: Telescopic fork Rear: Twin shocks, coil spring over
Brakes	Front: Single disc, 11in Rear: Drum, 7 in
Front Tire	3.00-18
Rear Tire	3.75-18
Seat Height	787 mm / 31 in
Weight	173 kg / 382 lbs (dry),
Recommended Oil	Suzuki ECSTAR 10w40
Fuel Capacity	15 Liters / 4.0 US gal / 3.3 Imp gal
Manuals	Service Manual

Engine

The engine was a Air cooled cooled Four stroke, parallel twin cylinder, DOHC, 2 valves per cylinder.. The engine featured a 9.1:1 compression ratio.

Drive

Power was moderated via the Wet multiplafe.

Chassis

It came with a 3.00-18 front tire and a 3.75-18 rear tire. Stopping was achieved via Single disc, 11in in the front and a Drum, 7 in in the rear. The front suspension was a Telescopic fork while the rear was equipped with a Twin shocks, coil spring over. The GS425E was fitted with a 15 Liters / 4.0 US gal / 3.3 Imp gal fuel tank. The bike weighed just 173 kg / 382 lbs.

Photos

Overview

Suzuki GS 425E

TWENTY-THREE. THERE'S A NUMBER TO conjure with. You may think there's absolutely nothing about the number 23 to commend it or make it special. Well, you'd be wrong, there's plenty. For a start, well . . . errr, lemme see. Oh yeah, John Keats was 23 years old when he wrote 'Ode on Melancholy', and that was no mean achievement. If you add 2 and 3 together you reach five, and your writer was five years old when he first mastered infinitesimal calculus. Ahem. Oh yes, and one other thing. Twenty-three is the amount of cc by which Suzuki have increased the volume of their GS400. Not only have they added 23cc, but they've renamed the bike the GS425. If that isn't a masterpiece of absurdity I'll ride GSs from now until Christmas. Hogging-out the 400 by 23cc has rekindled my faith in Japanese inscrutability. Eastern designers were becoming boringly logical in a Western kind of way. Gone are the days of the arbitrary displacement figure, such as the 360 and the 900 (although the latter has returned in a blaze of glory with the new Honda). Suzuki have taken the Blue Riband for meaningless — the 423cc motorcycle, called the 425. But why? Surely nobody who gave the original a miss is going to be attracted by this addition, unless of course the styling change is all they're interested in. Actually you couldn't blame them for that, it's a very slick looking bike. Ours was black with contrasting gold decals on tank and side panels, but couldn't they run to a bit of paintwork instead of tapes for the striping? Basically the motor is the same DOHC balance-shafted unit as the GS400. Red-lined at nine grand it appreciates being treated like a 2-stroke, ie held wide open and whanged through the gears. No, that's not what I mean, perhaps a better way of putting it is to say that the characteristics are such that it encourages you to treat it that way. There's a definite power band at the 4000rpm mark and I kept running out of cogs a lot quicker than I expected. The gearing wasn't altered along with the hop-up and the result is that it accelerates quicker than the 400 (which was no sluggard anyway) and turned in a respectable 14.75sec standing quarter. That's more than half a second faster. A flick back to Peter Watson's test of the 400 in May of last year also shows that with a few thousand miles under its belt, this motor loosens up considerably, to the tune of 10mph on the top speed. So maybe our 101.8mph top whack could be improved on later this year when the test bike has had a bit more of a thrashing. When I got on the bike for the first time I could hardly believe that it really was a 425, it felt so small and low, and this was enhanced by the riding position. The bars are practically flat and at 27ins wide they're narrow too, but I felt the footpegs could have been moved back three or four inches to increase rider-lean and reduce the feeling of being perched on top of and a third of the way back on the machine. This position did tend to make me feel a bit exposed on high speed bashes but I can't complain about the comfort, it's a nicely padded seat and there were no aches or pains apparent after a motorway thrash. Incidentally, Timmy, that long-legged denizen of the Bike office, complained that the most comfortable riding position for him on this bike meant that his knees rubbed on the Suzuki decal and they did get chappie chapped. The handling hasn't changed with the motor, it is still very rigid and totally predictable. During most of the test period the country was under a few inches of white stuff which made assessment of the handling a little difficult. However, crossing London in good weather in the rush hour was fun, the general narrowness of the bike and its zoom-ability made it a great traffic dodger. Funnily enough, although the front end felt heavy (it dived like a U-boat under braking) it was from this department that I got the only negative vibes in the handling department. On long high speed corners there was the tiniest hint of front wheel flutter but I'd be inclined to put that down to the Jap Dunlops fitted as standard. Here's one of those weird contrasts I was talking about: Suzuki build themselves a great little frame based on the GS750, put on some of the nicest mag wheels you're ever likely to come across and then spoil it all with rubbish tires. They are inscrutable, these orientals. Or are they just cheapskates? A single 11 in disc up ront and a seven inch drum behind provide the stopping power, and very effective they both are too, despite the way the forks dive. Of course, any rain reduces the disc to the efficiency of a piece of soggy cardboard. Mechanically it's a very smooth and qujet engine, at high speeds you get a slight tingle through the bars but nothing to write home about. The balance shafts and 180 degree crank do their jobs very well. Noise is kept to a minimum because there are only two chains on the whole bike, one to the back wheel and another driving the cams. There's a nifty little automatic camchain adjuster too, a spring driven gizmo that hangs out under the carbs on the right hand side of the bike. While we're in the area of the two 34mm Mikunis another contrast rears its head. When will the Japs give us carb fitments capable of a little English weather? Corrosion was very bad on the hose clamps, choke lever, throttle return spring and all the other linkages. Would it cost too much to have them plated before leaving the factory? And so to the choke and general starting of the bike. Not too hot I'm afraid. In the handbook it tells you to switch on the choke, press the starter (there's a kickstart too) and then, using the choke lever, regulate the revs to 2,000 for 30 sec in summer, longer in winter, before moving off. Well, that's all fine and dandy but I never could get the revs above 1,000 on the choke anyway and during the very cold weather it took a long time for the engine to warm up. It didn't help to leave the bike ticking over on choke for a while before getting on, because after a while the revs would falter and die. As soon as you open the throttle it by-passes the choke anyway so if you forget about it you find yourself arriving at the first set of traffic lights, closing the throttle and then wondering why the engine stopped. That's just a niggle though. Two more annoying points were a steering lock that was jammed (in the off position thank God) and the fact that you still have to dismantle the left-hand exhaust to get the back wheel out. Jeezus, I thought that went out with 750 Commandos.

The instrument console is pretty impressive, and just plain pretty, too. Across the top is a clear and helpful digital gear indicator, underneath that a main beam light, indicator light and neutral light. The dials keep their seductive rosy glow at night. Sensibly, Suzuki have re-calibrated their speedo to show the all-important 30 and 70mph marks but the instrument error was pretty bad, giving 27.08mph at an indicated 30mph and 54.30 at an indicated 60. Lighting is adequate but nothing special, and dip beam failed after a time. The other switches and electrics keep up the famous Suzuki standard, however. One complaint in the handlebar area was the mirrors, they're a strange design. There's a post that screws onto the switch console with a branch into which the mirror stem screws. The mirrors swivel at the top. Despite three adjustment points I found it hard to get a good rearward view without a good dose of elbows showing.

Source Bike 1979

Make Model	Suzuki GS 425E
Year	1979
Engine Type	Four stroke, parallel twin cylinder, DOHC, 2 valves per cylinder.
Displacement	423 cc / 25.8 cu in
Bore X Stroke	67 x 60 mm
Compression	9.1:1
Cooling System	Air cooled
Induction	2 x 34 mm Mikuni carburetors
Starting	Electric and kick
Clutch	Wet multiplafe
Max Power	29.8 kW / 40 hp @ 7000 rpm
Transmission	6 Speed
Final Drive	Chain
Front Suspension	Telescopic fork
Rear Suspension	Twin shocks, coil spring over
Front Brakes	Single disc, 11in
Rear Brakes	Drum, 7 in
Front Tire	3.00-18
Rear Tire	3.75-18
Seat Height	787 mm / 31 in
Dry Weight	173 kg / 382 lbs
Fuel Capacity	15 Liters / 4.0 US gal / 3.3 Imp gal