Commuters, also-rans & alternatives: Suzuki four-stroke twins
This month Steve Cooper untangles the many Suzuki twin models of the 1980s.
Mention Suzuki twins and most of us will go off on tangents, wistfully remembering the T series strokers from 125 through to 500cc. From the iconic Stinger through to the Cobra/Titan, the Hamamatsu factory turned out some real belters. Qualify ‘Suzuki twins’ by adding in words such as cams or valves and most will happily try to change the subject pronto! Often cursorily dismissed as substantially less than adequate, few would give them a second glance. Some of Suzuki’s sub500 four-stroke twins were arguably an acquired taste, potentially toxic or downright odd; yet others were really good machines that somehow just got variously ignored and/or maligned.
Arguably the best of the lot were the GS400s that first saw light of day in 1976 when they were launched at the same time as the groundbreaking GS750. Graced with double overhead cams and an electric starter, the GS400 was effectively the then modern version of the previously all-dominant Honda Super Hawk of the 1960s. The GS400 would run, pretty much unaltered other than aesthetics, from 1976 to ’78 before being revised to deliver the GS425 and GS450 and then ending up as the GS500E of 1980. All of these twins drew much of their DNA from the fourcylinder GS750 and were none the worse for it. The only real significant issue with these understated twins was the curious way Suzuki had arranged the charging systems which gave numerous dealers and countless owners untold sleepless nights.
Quite possibly just because it could, during the lifetime of the GS series Suzuki decided to reinvent the genre once again using a dohc design, but this time with supposed ‘added refinements’. Everything was based around the then revolutionary TSCC or Twin Swirl Combustion Chamber that was designed to increase the gas flow through the cylinder head which sported four valves. Unusually for a Japanese firm, Suzuki had bought in an external consultant to up the ante on its earlier GS motors running two valve cylinder heads. Italian engineering guru Vincenzo Piatti was the man that drafted the all-new, four valve head and his ideas and designs, in modified formats, would still be in use by Suzuki decades later.
If that name vaguely sounds familiar, then perhaps it should. Piatti is the man who designed a range of two-stroke singles for AMC when the conglomerate decided to walk away from long-time business partners Villiers. History records that the Piatti-designed 175, 200 and
250cc singles were woefully unreliable whereas the truth was that AMC’s various machine shops were unable to work to the fine tolerances the Italian’s designs required. Needless to say, Suzuki was able to comply with Piatti’s requirements to deliver what was needed.
The concept had first been seen globally on the GSX750E of 1980 and was very rapidly rolled out to most of Suzuki’s four-stroke multis.
From here onwards the list of four valve dohc Suzuki twins almost spiralled out of control. First out of the blocks was the GSX400E sold in Japan for the 1979 model year and this model continued through to 1986 before being replaced by a watercooled version. Running concurrent with the 400 was the GSX250E that was sold into the UK for a few years and this was one of the learner machines that competed against Honda’s Superdream in the key 250 market.
In isolation, the GSX250E was a good enough bike, but, by the time they’d been through half a dozen learner riders’ hands, many were suffering, to say the least. Flapping cam chains, maladjusted valve clearances, blocked or missing air filters and the like swiftly gained the 250 twin a poor reputation.
Overseas the dohc motor would be pressed into service in a factory custom cruiser sold confusingly as the GS300, but if it had ever been marketed in Europe it would have been theoretically marketed as a GSX300… possibly. The GSX moniker was used on both twins and fours almost willy-nilly and, to add further confusion, some later four valve twins running the TSCC set-up would be badged as GS models.
The original GSX400 was soon upgraded to 450 giving rise to yet another raft of versions. The GSX450L was another faux cruiser, the GS450E a naked doeverything middleweight, the GCS450S little more than a 450E with a bikini fairing with fancy paint job and then the GS450TX which appeared to be the same as the 450L but with wire wheels in place of cast alloys. And, pausing to draw breath, finally the GS450A which was essentially the 450TX, but this time equipped with a two speed semi-automatic transmission.
All of which, you might quite reasonably think, was more than enough bases covered but no... 1989 saw yet another variation on the theme with a GS500E twin which, obviously, should not be confused with the similarly named GS550E four! The ‘all new twin” (yeah, right!) now sported a perimeter twin beam frame, not unlike Yamaha’s delta box design and running ‘Full Floater’ rear suspension. Despite all the benefits conferred by the TSCC head, the
GS500E reverted to a simpler two valve arrangement as per the original GS400 – are you keeping up with all this?
In this guise the bike remained in the model line-up from 1989 through to 2009 before being supposedly pensioned off, giving Suzuki a rather good return on its original designs. If some thought that might be end of the line for the model, they were wrong. Until its closure in
2013 the Spanish factory in Gijón was still making iterations of this grand old dame when the Colombian Pereira site took over. Folk might scoff at Suzuki’s middleweight twins but the bank balance tells a rather different story!