was the first vertically mounted single rear shock and it
used linkage—clearly the forerunner to virtually all of
today’s rear-suspension designs. In practice, it didn’t
live up to its potential. The lever ratio was actually
regressive, getting softer as the swingarm moved
through its arc. Kawasaki engineers refined the system
for the next few years, making it better and better. The
420 motor, though, wasn’t a stellar performer. It was
outpowered by most of its classmates, most notably the
stunning Maico 490.
1983: The KX500 is born. Kawasaki might have had the
biggest bike in the class, but that didn’t translate to performance. It was fast, but had a poorly designed combustion chamber that resulted in self-destructive tendencies.
The compression had to be lowered, and that killed any
performance edge it might have had. The good news was
that Kawasaki had redesigned the chassis and, for the first
time, had excellent suspension.
1985: This is the first of the great KX500s. It got a new
motor with liquid-cooling and it was, for the first time in
Kawasaki’s history, the best bike in its class. The Honda
CR500R of the time was faster, but had terrible power
delivery and wicked handling. The next year, Kawasaki
gave the KX a feature that no other 500cc two-stroke had
ever seen: a KIPS power valve.
1987: Updates came yearly in this period, as
Kawasaki and Honda were locked in a battle for dominance of the class. All the others had fallen by then;
Suzuki’s 500 was long gone, and Yamaha’s air-cooled
YZ490 was still in the line, but rapidly becoming an
antique. The Kawasaki got a new frame and the side-access airbox design was abandoned. The rear suspension was reconfigured, losing the big rocker arm on top.
1988: The KX500 got its last big redesign, becoming
the bike we know and love. It got minor mechanical
changes and cosmetic updates afterward, but the most
In 1990, Wardy won his second consecutive 500 championship. He ended his career with 12 overall wins in the 500
class. Extra credit: Which Kawasaki rider had more wins?
significant event was the arrival of the upside-down fork
in 1990. In 1992, the ignition and crank were changed
as an unofficial acknowledgment that the KX was being
used more for off-road riding than motocross. By the
early ’90s, Honda had given up the horsepower chase,
leaving the KX uncontested as the most powerful dirt
bike made. There was a brief challenge from KTM in the
500 class, but the only years that proved formidable
were 1991 and 1992. There was also a KTM 550DXC in
that period that was a very good bike.
Kawasaki KX500s are plentiful on the used-bike market,
particularly in the Southwest. A quick survey on Craigslist
shows prices between $500 and $2400. With a bike that
was unchanged for this long, it’s all about condition, not
vintage. Few of them were raced, although many appear
unkept. Parts are readily available for anything that was
manufactured after 1990.
One of the great things about used KX500s is that
they are fairly indestructible. They could swallow dirt by
the pound and keep running. The electrofusion-coated
cylinder couldn’t be bored, but would wear for a long,
long time. If it does get damaged, there are a number of
companies like Millennium Technologies that can recoat
a KX barrel.
At the height of the Team Green desert racing era, the
most significant modification was frame reinforcement.
The KX frame wasn’t nearly as indestructible as the
engine. The pipe mount and footpeg mounts always got
attention. Zip-Ty Racing still has a long list of KX500 parts
and services available.
The fleet of KX500s is so large that it’s somewhat eternal on trails in California and Arizona. And, there’s always
talk of a renewed race effort in Baja and District 37. Why
not? It’s never really been established that there’s anything
ICONIC DIRT BIKES
Ward’s 1989 championship-winning SR500 isn’t so far
removed from the production KX.