Commuters, Also Rans & Alternatives: Kawasaki disc valve singles
Generally this page looks at a single motorcycle and its development but this month we’re focusing on one of the most successful power units ever built – and, no, it’s not a C series Honda for once.
Instead we’re having a peek at a very simple yet robust disc valve two-stroke that powered a raft of small Kawasakis over almost five decades!
This seminal motor began life as an 85cc unit in the 1965 J1 commuter bike that sported a rotary four-speed gear shift arrangement. Expanding on what was a very sound machine, Kawasaki soon fitted high pipes, raised front mudguard and, in some instances, knobbly tyres to variously offer sports versions and simple if primitive trail machines.
A whole five cubic centimetre increase in capacity delivered the G series, which were exported to a wider market than the earlier J models.
The late 1960s saw the power increase from 8.20 to 10.5bhp, which may not sound like much, yet this 20% hike saw the little 90s quickly gain a reputation for being peppy performers.
Quite possibly one of the first Kawasakis to be imported to the UK was the GA2A. This handsome chap came with mainly white panels contrasted with candy blue or red on the tanks and suspension units. Many an unassuming commuter was pleasantly surprised by just how fast these cute so-called commuters actually were. Looking to get maximum return on the initial design, the 90 unit also appeared in various small trail bikes sold as MC or KM models.
The G series proved to be exceptionally popular and ran on into 1974, with the final GS3SSD model borrowing the classic D-shaped decal from the triples of that year.
The following model year saw the G3SSE on sale, fitted with a 100cc motor that still owed so much to the original J1 a decade earlier.
A year later the bike was rebranded as the sporting KH100 (Kawasaki Highway) and it would go one to be one of Kawasaki’s longest -running lightweight machines.
So, you might reasonably assume that all 100cc Kawasaki commuters would be labelled KH, but not a bit of it. For reasons that really aren’t apparent, the G series 100s continued to be offered for sale in certain markets, reaching as far as the G7 model before being pensioned off.
Rewinding a little, we find that certain areas of the Kawasaki’s distributorship were keen to sell pukka 100cc trail bikes, all of which were based around the road-going G4. At least 10 different models were offered over the years, with some specifically sold as ‘Agri bikes’.
These machines were equipped with huge mud flaps, headlight/instrument crash protection cages, seriously robust rear racks, enclosed drive chain cases, brush guards front/rear and even a holder for a shovel! Not too surprisingly, these bikes were popular with farmers.
Some might have thought there were sufficient variants, but no – a subset of the G4 off-roaders appeared in the mid to late 1970s, stripped of some of the essential farming hardware but still sporting chain cases and racks and sold as the KV series.
Building on the successes of the trail bikes, someone in Kawasaki’s marketing department saw an opportunity to gain more of a market share through further reworking of the off-roaders by fitting a different, high airflow cylinder head and revised exhausts to deliver the KM100 series. Despite the KM (Kawasaki Motocross) moniker, the various examples all sported lights and indicators, making them road legal.
Stripped of such fripperies the bikes were labelled as KD100s – the KD meaning Kawasaki
Dirt, apparently. Any sane person might think all possible permutations had been considered, but again no – taking trim parts from the G ranges and the chaincase of the Agri bikes saw the robust and doggedly reliable KC100 (Kawasaki Commuter) created, which served many UK riders well as a basic rideto-work machine.
Are we done? What do you think? Once again 1976’s rebranding saw the G4/5 trail irons reworked as the KE of Kawasaki Enduro range, which prove to be hugely popular globally.
Following its renaming, the KE100 would go on to become something of a runaway success, with the final models being sold as late as 2001. Only emissions regulations finally sealed the little KE’s fate, but it had enjoyed an unparalleled success and given its ancestry, the power unit had enjoyed a 36-year lifespan – something almost unheard of in the Japanese automotive industry!