The 250cc A1-R was released in 1967 and was closely based on the A1 Samurai road bike. The frame was basically the same but with additional bracing.
The rotary-valve motor had numerous changes however, including pressed-in iron cylinder liners with modified porting, thinner (1 mm) piston rings, magneto ignition, straight cut primary gears and closer ratios in the five-speed gearbox.
Racing 26 mm Mikuni carburettors with remote float bowls were fitted. Output was around 40 hp at 9500 rpm, compared to the A1’s 31 hp at 8000 rpm.
Noted Kawasaki racer Dave Simmonds achieved fourth place at the ’67 IOM TT and a fifth at Assen to finish 10th in that year’s 250 cc World Championship.
About 150 A1-Rs were produced during ’67-’68 before the A1-RA became available in ’69.
This original bike has a motor from one of the “works” bikes that were developed and campaigned out of southern California.
One of our readers was able to add further information about the A1-RA:
“The article by Phil Aynsley on the Kawasaki A1R is good concise history of the machine. There is one point which he makes that is incorrect. The A1RA was never available, there were six A1RA and three 7RA prototypes built for Daytona in 1969.
“Of these three A1RA’s were broken up for parts. One of the A7RA’s was fitted with a 500cc triple (by Tony Nicosia, working with Kawasaki in Japan) to become the prototype for the H1R.
“One of the A1RA’s which was broken up has been reconstructed in a replica frame and is in the USA, making four A1RA’s and two A7RA’s extant.
“Subsequently four further machines were built for the Singapore GP. These were significantly different the A1/7RA machines and designated A7RS and A1RS.
“Of these three survive in original form, an A7RS in the Kawasaki museum in Kobe Japan, an A1RS in private hands in Japan and an A1RS (ex Ken Blake) is in Australia.
“The remaining A7RS is also in Australia but has been fitted with a 350cc triple. The engine numbers for these machines run from KAE1001 to KAE 1013 and the Chassis numbers for the A1/7RS machines run from 20FP01 to 20FP04.”
And here is a video we found of an A1-R being fired up recently
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