Two stroke, transverse three
cylinder, piston valve
Capacity
498 cc / 30.4 cu-in
Bore x Stroke
60 х 58.8 mm
Cooling System
Air cooled
Compression Ratio
6.8:1
Lubrication
Injectolube, automatic pressurized injection
Induction
3x Mikuni VM28SC carburetors
Ignition
CDI
Starting
Kick
Max Power
60 hp / 45 kW @ 7500 rpm
Max Torque
56 Nm / 42.3 lb-ft @ 7000 rpm
Clutch
Wet multi-disc
Transmission
5 Speed
Final Drive
Chain
Frame
Double tubular steel cradle
Front Suspension
Telescopic hydraulic forks
Rear Suspension
Dual shocks, swing arm
Front Brakes
200mm Drum
Rear Brakes
180mm Drum
Front Tyre
3.25-19
Rear Tyre
4.00-18
Wheelbase
1400 mm / 55 in
Dry Weight
174 kg / 384 lbs
Wet Weight
188 kg / 414 lbs
Fuel Capacity
15 Litres / 4.0 US gal
Standing
¼ Mile
12.4 sec
Top Speed
200 km/h / 124 mph
History
The market for motorcycles in 1968 had been changing from time, utilitarian
transport to more aggressive sporting motorcycles that disregarded fuel economy
and noise, in favor of quicker quarter mile times, which were prominently
advertised by manufacturers. While Kawasaki had an inline-four four-stroke in
development, it was not going be ready in time to upstage the 1969 Honda CB750,
so instead they moved up the release of their conventional piston port
two-stroke triple to "make a real splash". They turned to the N100 Plan, a
project begun in June, 1967, whose intent was to design the most powerful
production motorcycle engine in the world. They first considered increasing the
bore of an existing engine but instead created an all-new engine, experimenting
with both inline and L cylinder arrangements, with both two and three cylinders.
They settled on an inline-three arrangement after testing showed that an
inline layout did not adversely affect cooling of the middle cylinder.
The result of this project was the H1 Mach III, with a 15° inclined,
inline-triple 498 cc (30.4 cu in) engine, first produced in September, 1968, 14
months after the N100 project began. The new model did indeed sell well with
young men in the late 1960s, with total production eventually exceeding 110,000
units, though it was unpopular with authorities. The bike gave Kawasaki a
"rebel" image, "outside the law", which played well with sport bike riders. The
racing version, the H1R ridden by Ginger Molloy, took second place in the 1970
Grand Prix World Championship.
The H1 was the first multi-cylinder street motorcycle to use capacitor
discharge ignition (CDI) which operated through an automotive style distributor,
previously only used in off-road single cylinder motorcycles. The first version
of this electronic ignition was overly complex and proved unreliable, so
Kawasaki gave up on it briefly, using traditional breaker points, one set for
each cylinder, in 1972. For the 1973 H1D, a redesigned CDI was used, which was
more reliable with a hotter spark at lower engine speeds, which in turn made it
possible to re-jet the three Mikuni carburetors for a wider power band. The US
version came with a high handlebar, but a low bar was used in the European
market. The H1 was loud, due to the use of racing expansion pipes, brought
barely within the limits of noise regulations for the period.
The bike had both detractors and enthusiastic fans, who either complained of
poor handling and tendency to wheelie, or praised the power, light weight, and
tendency to wheelie. Wheelies could occur unintentionally even during cornering.
The two-stroke engine's suddenly increasing power curve, with little response
until a rush of power about 5,000 rpm, contributed to this unexpected liftoff of
the front wheel, creating "fearsome reputation" from tales of "scary
performance." The Mach III became known to its critics as "dangerous for
inexperienced riders".
The H1 had a high power-to-weight ratio for the time, 45 kW (60 hp) and a dry
weight of 384 pounds (174 kg), comparable to a top racing motorcycle, but had
generally poor handling and weak drum brakes front and rear. It could accelerate
from 0 to 1⁄4 mi (0 to 0 km) in 12.4 seconds. However, Motorcycle Classics said
in 2009 that the frequent complaints about the brakes of the H1 by modern
writers did not account for the generally poor braking of all motorcycles of the
period, noting that in a 1970 Cycle magazine comparison of seven top sport bikes
of the time, the H1's braking performance was second only to the Honda CB750.
The notoriously flexible frame was strengthened over the years, along with
shifting the center of gravity to decrease the tendency to wheelie. While
Kawasaki was working to "make the H1 acceptable in civilized society", they also
released the delayed inline-four four-stroke, the Z1, in 1972, which had
adequate brakes and handling, comfortable seating, and did not guzzle fuel. The
sales success of the Z1 demonstrated that there were more buyers for
higher-priced but less obnoxious sport bikes, than buyers who would accept
numerous compromises for an extremely fast motorcycle at a low price. More
stringent noise and pollution regulations also contributed to the end of the H1
500 production, whose final year was 1976.
The Mach III H1 500 subsequently has been of great interest to collectors and
historians of motorcycles, often appearing on lists of most significant
motorcycles and, with some irony, "worst bikes" lists. Cycle World
semi-seriously joked that the bike was one of the "10 Worst" for its total
compromise of good qualities other than speed, and that the bike "introduced" to
America the body cast and liability lawsuit. The H1 was included in the
Guggenheim Museum's 1999 The Art of the Motorcycle exhibition in New York,
Chicago, Las Vegas, and Bilbao, Spain.
Motorcycle historian Clement Salvadori noted in the Guggenheim's catalog that
the H1, "was one of the least useful motorcycles available on the market" yet
still sold very well because, in the heyday of American muscle cars where
quarter mile times were paramount to the young male target buyer, it "could blow
just about anything else off the road — for less than $1,000." Roland Brown
agreed that it could "beat almost anything away from the lights." Salvadori
added that "Motorcycle lore has it that very few original owners of the Mach III
survived." While older Baby boomers collected classic brands of the 1950s and
1960s like BSA, Norton and Triumph, a younger generation of motorcycle
collectors was nostalgic for H1 Mach IIIs along with other bikes of the era,
Honda CBs and CLs, Yamaha RD350s and Suzuki Hustlers.
Source Wikipidia
Any corrections or more information on these motorcycles will be kindly appreciated.