New in 1973 was an electric start and double-down-tube-frame to make the bike look bigger and more like a Harley-Davidson. They also changed to a larger Dellorto 30mm carburator compared to a 27mm Dellorto as used on earlier Sprint. This produced an extra two horsepower of now “27”. One great enhancement is the change to a 12V alternator with model year 1973. It also had a five gear transmission.
This is also the only production Aermacchi ever equipped with an electric start motor which easily started the 344cc engine but was as easily destroyed by engine backfire. The bike was fitted with a 12V 18Ah battery.
Because of the new (frame) design and the electric start motor a the bike was a few kilogramms heavier than earlier Sprints.
Between the 1973 and 1974 models they made only slight modifications like changing the decals on the gas tank. Late ‘ 74 models also had a new clutch system. The 1974 SS-350 is the last year of the Aermacchi 4-Stroke Bikes and the end of an era. After that, there were only 2-Stroke bikes available from Aermacchi.