Stumbled upon this on the UK Tinternet under Kawasaki Triple Images. It actually reads that the bike is a KH750 Cafe Racer!!
no suprise their then, anyway nice photos & as you will see on the last picture it is infact built by none other than John Aylor 
It states that it is infact a modified KH500 frame with H2 motor, all the same its very nice
Come here their's more I thought this was interesting From Wikipedia although some of the txt is a little wishy washy it is an interesting read all the same & is realy aimed at readers not familar with our beloved bikes!!
Kawasaki 750 Mach IV
The Kawasaki Triple is a generic nickname for a range of motorcycles Kawasaki Heavy Industries (Japan) produced. This range of motorcycles ranging from 250cc to 750 cc were built and exported from 1969 to 1980. The name comes from the motorcycle's unconventional engine layout, an air cooled three cylinder two stroke with two exhaust pipes exiting on the right side of the bike and one on the left.
The first Kawasaki Triple was the H-1 Mach III 500, introduced in 1969. The original H-1 was unique for using a CDI ignition which operated through an automotive style distributor. The H-1 offered a high power to weight ratio for the time period, but also generally poor handling and weak drum brakes front and rear. It was the quickest production motorcycle at the time. When motorcycle journalists expressed some disbelief, Kawasaki suggested they take a new H-1 to the drag strip. Using a regular production model with only 7 miles on it, Tony Nicosia ran the quarter mile in 12.96 seconds at 100.7 mph for the press to witness. Tony Nicosia set many world records with Kawasaki triples over the following years, including some land speed records at Bonneville Salt Flats.
In 1972, the 750 Mach IV was introduced. Updated with more power and better front disc brakes, the 750 became the undisputed king of the streets, even beating legendary muscles cars of the era such as the Dodge Hemi Cuda. However, wobbly/dangerous handling caused it to be nicknamed the "Widowmaker".
The ability to cheaply modify the engines for higher performance by porting the cylinders, milling the cylinder heads, and installing expansion chamber exhausts maintained their popularity for some time in drag racing. A 750 H-2 still holds the record for the fastest nitrous injected 750 cc motorcycle, with a standing quarter-mile of 7.776 seconds at 170 mph by Brian Pretzel of Redline Motorsports and the fastest normally aspirated 750cc motorcycle with a standing quarter-mile of 8.24 at 153 mph held by Joe Bird of Fremont Nebraska.
In 1974, the 350 cc S-2 was expanded to a 400 cc S-3. In addition, the model range was toned down in performance. The H-2 ceased production in 1975, and the model line became the KH series in 1976. United States production stopped in 1976, while the 250 cc KH-250 and 400C KH-400 continued in Europe and elsewhere until 1980.
The S-1 was popular for some time as a budget performance bike in England because of its small size. The entire S series of motorcycles used breaker point ignition, which was more reliable than the early CDI ignition and much cheaper to repair or replace.
An interesting offshoot of the Kawasaki Triples was that since they were air cooled and the crankshafts were pressed together, it was possible to literally cut an engine apart, press up extra sections of the crankshaft, re-weld different sections of the cases, and make multi-cylindered motorcycles. The ignition system had to be redone, as well as the carburetors. Four cylinder 1000 cc H-2's were known to exist,[citation needed] but the most common bikes to be modified were the S series, with 5 to 7 cylinder models being built,[citation needed] and at least one "V-6" (two three cylinder banks feeding into a common transmission). More of a machinist's skill exercise than a practical development, they were still a popular modification in Europe. They were impractical because the engine was made much wider and the clutch and gearbox were put under more strain.
Not sure about this bit though unless Sir Rick can throw some light on it
Another modification was a liquid cooled H-2, which was done in the late seventies in either Australia or New Zealand.
Brief model summary:
1969
H-1 500 cc white w/blue stripes, distributor CDI ignition, drum front brake, "Mach III 500" badge on side cover and "electronic ignition" decal on oil tank. Late 1969 saw the introduction of the Charcoal Grey model
1970
H-1 500 cc red w/white stripes on the fuel tank.
1971
H-1A 500 cc, style redesign without the Mach "III" badge, blue with stylized stripes on the fuel tank.
1972
Entire line introduced, intended to be similar in style, with the "swooping" racing stripes on the tank that distinguished the triples.
S-1 250 cc, white w/green stripes.also in red S-2 350 cc, red,also in white drum front brake
H-1B 500 cc, orange, disc front brake, CDI dropped for breaker points, and a front disc brake.
The H-1C was we believe the Kawasaki factory using up its leftover parts. It had CDI instead of the points on an H1B and also a front drum brake as opposed to the disc on the earlier H1B. Also a few cosmeticchanges.
H-2 750 cc, Blue or Gold - Gold versions were in the early production run and went to the home market of Japan, Australia / Southern Hemisphere and Europe but not to the U.S.A., front disc brake, CDI ignition with one igniter unit per cylinder.
1973
S-1A 250 cc Gold or orange
S-2A 350 cc Orange or Blue.
H-1D 500 cc Adopted H2's CDI ignition and the styling that would be used on the later 1974 models.
H-2A 750 cc Purple/Gold.
1974
All models restyled with a new cleaner design that resembled the Kawasaki Z-1, with an instrument "pod" rather than separate instruments. All models revised for more civilized performance at the expense of raw power.
S-1B 250 cc green, front drum brake.
S-3 400 cc blue or red, disc front brake, restyled cylinder head design for better cooling.
H-1E 500 cc green or red.
H-2B 750 cc brown/green.
1975
S-1C 250 cc blue.
S-3A 400 cc Green or Red.
H-1F 500 cc brown or Blue.
H-2C 750 cc red/purple.
1976
H-2 dropped from line, models renamed "KH" to match the "KZ" line of four strokes.
KH-250 250 cc.
KH-400 400 cc.
KH-500 500 cc.
1977-1980
Only surviving models are the KH-250 and KH-400.
KH-250 250 cc.
Delboy
