Kawasaki 1968 A7SS Avenger Scrambler

1968 A7SS Avenger Scrambler

These photos were taken of my 1968 Kawasaki Avenger A7SS 350cc, 2-Stroke Rotary Valve Twin. Always the “other guys” – Kawasaki motorcycles were kind of dark and definitely different. Kawasaki did and still does build some amazing machinery. These bikes are kind of rare and hard to find, especially in original condition since they never made it to mainstream numbers. Their performance reputation was also alluring to the Go Faster Crowd who tend to use everything their machines can offer.

flag on mirror

Have a look at the Flag Emblems all over the bike. Kawasaki Heavy Industries made ships – big, massive, ocean-going ships at that. They made trains and all kinds of industrial sized equipment. Look closely and you’ll see they have proudly placed Nautical Flags on just about every part of this 1968 Avenger.

350ss Avemger

Now for more on that performance reputation, Kawasaki was not going to be ‘just another motorcycle maker’. They kept most projects outside of the box. While their Samurai 250cc was light and fast, 30 horsepower was not enough. They wanted more. The Kawasaki Avenger 350’s made 42 horsepower! Compare that to any of it’s rivals before and after – Yamaha’s little 350 “Giant Killer” made 34 hp in R5 form and 36 in RD form (reed valves). The Honda 350’s claimed 36 hp, while the GT380’s from Suzuki made 34. The Avengers out powered them all making these real sleepers. In Street trim and gearing, there are reports of low 13 seconds and 90+ speeds in the quarter mile. The 1968 Avenger did 105 mph during it’s magazine test and left black marks all over the highway getting there. Very impressive for 1968, even more impressive for an air-cooled 350! The legendary 500cc Mach III’s would have been Rotary Twins using the same Rotary Valves set-up, but engineering concerns over mounting carburetors on the ends of the crankshaft and a more rubust clutch design pushed Kawasaki into the 3 Cylinder “Triples” design so infamous today – That’s another chapter we’ll soon post stories and information on.

the caburetor

Browse these photos and you’ll miss the carburetors. They aren’t mounted in the front or rear of the cyclinders as convention would have it. Kawasaki used Rotary Valves attached to the crankshaft. These spun at crankshaft speeds and the carburetors sit ‘sideways’ at both ends of the crankshaft. As the crankshaft rotates, the intake timing is controlled by the rotating disc that is precisely notched to let fuel/air into the crankcase so the downward motion of the piston forces the charge to the top of the combustion chamber. This solved the reversion problems of normal “piston ports” and did so without using reed valves. One of Kawasaki’s out-of-the-box machines with 42 horsepower that towered over all competitors in the same displacement for years.

This one found a new home last year in a museum in North Dakota. I never rode it and when Terrie says something’s gotta go – this was one of those I was never going to ride.

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