Mr Reynolds, who’d helped keep the Scott name alive by bulk buying complete machines and parts which were used to build his Reynolds Specials (earlier Aero Specials) during the hard times of the early 1930s to help the factory’s cash flow, had been working on a single cylinder 250cc design as well as the twin. As with earlier Scott powered Reynolds Specials, the new AER was launched in the IoM during TT week, but many UK mainland based parties waited until July to examine the machine at the Reynolds shop.
With bore and stroke dimensions of 57 x 66.7mm, the air-cooled twin-cylinder engine displaced 340cc. While the crankcase comprised four castings, the pair of all alloy cylinder heads were cast as one as were the barrels which had pressed in liners. The built up crankshaft carried a flywheel to the right while a pair of sprockets on the left drove the Pilgrim oil pump and the primary drive chain. With mid-machine height exhausts the AER was fitted with an Amal carburettor and Burman four-speed gearbox.