Also, a two-time Daytona 200 winner and 24-time AMA National race winner among other titles. Competing in 230 AMA nationals, in dirt track, road races, and motocross and winning in every category of the AMA Grand National competition. Mann is revered as a hero of American motorcycle racing having won more races in more categories than anyone else. The engine wasn’t the only interesting thing about the Ossa Yankee 500Z because the frame was overseen by no other than Dick Mann. The gear ratio of the six speed box was 4.2:1, which meant it had an exceptionally wide spread, the small speed differential between gears meant that clutchless shifts were easy to attain. Electronic triggers fired two separate ignition coils which counted for the 180° firing interval option. The engine had a bore and stroke of 72mm by 60mm and two 24mm IRZ 4G dual-needle carbs, and the bike a 6-speed gearbox. The cranks were spaced at 360° so both cylinders fired together but they could be reset at a 180° interval if needed as Taylor thought the engine could be used for road racing too.
The engine was forward facing in the chassis at Taylor’s demand for his preferred weight distribution. Giro did this by using two 250cc Ossa Pioneer top-ends, inclusive of the pistons, cylinders and heads, two seperate crankshafts which ran on ball bearings and connected by a central sprocket, in a joint two-cylinder engine case. The engine designed by Eduardo Giro, was a modified twin-cylinder 460cc Ossa road race engine turned into a 488cc dirt bike engine. Taylor wasn’t ready to give up on his American Dream, where many would have folded, John Taylor forged on. When the bike was finally in production, the import price of the Ossa engine doubled as a result of the Nixon administration abandoning the gold standard and in turn devaluing the dollar.
They had also just been rocked by the death of their star rider, Santiago Herrera, at the Isle of Man TT. However, it took 4 years before Ossa got the Yankee 500Z into production in 1971, this was because they were chasing Grand Prix ambitions of their own. The first plans were shown to the press in 1967 and the first prototype built in 1968. Taylor used his connections for this as he was the official Ossa importer for the US. Ossa was the small Spanish firm commissioned to build the drivetrain for the Yankee. It took a lot of persistence and many years before the Ossa Yankee 500Z was to be produced and to fulfill Taylor’s dream. It would be the bike for everyone and every purpose. Taylor had a dream and that was to build an American big capacity enduro bike capable of competing against the European motorcycles and bring it to market. He came close to owning the Bultaco factory in Barcelona. He was responsible for Bultaco producing the popular 200cc (250cc and later 300cc) Matador street-scrambler for the U.S market. Taylor was an entrepreneur making his money from importing bikes into the US. The story starts with motorcycle importer John Taylor and the Ossa Yankee 500Z would become what he is most infamous for in the motorcycling world.
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