Yankee, who gambled on the big, twin-cylinder, six-speed, Yankee 500Z, was owned by John Taylor, who was both the American Bultaco and Ossa importer. John had a dream to build the ultimate American off-road bike. To achieve this, he talked Ossa into modifying a twin-cylinder, 460cc, Ossa road race engine, designed by Eduardo Giro, into a 488cc dirt bike engine by mating two 250cc Ossa Pioneer top-ends, including the pistons, cylinders and heads, onto a unified two-cylinder engine case.
Dick Mann designed the large tubing frame on the 500Z. Dick had also built a dirt track frame for Ossa—which was marketed as the Dick Mann Replica (DMR). Less than 200 of these Ossa-powered flat trackers (bearing Dick’s name) were produced and when the 1971 Yankee 500Z began to languish in the sales department, John Taylor pinned his hopes on building a lighter, 460cc, single-cylinder motocross bike and had Dick Mann design a down-sized frame to house the smaller single-cylinder engine. The Yankee 460MX borrowed the Kelsey-Hayes rear disc brake from the 500Z, but used a front drum brake from a Husqvarna. The Dick Mann influence showed in the large-diameter tubing, double-cradle frame with its oval section swingarm.
Surprisingly, even though John Taylor was the Ossa/Bultaco importer, he went to Switzerland to spec a 460cc, air-cooled, piston-port, two-stroke Motosacoche engine. The Motosacoche engine was incredibly modern for its time, especially when compared to the Ossa powerplants. The Swiss engine had many modern features including a twin spark ignition with two plugs (with the second plug’s timing retarded for a fuller fuel burn). Carburetion was via a 36mm, double needle, IRZ carburetor. All in all, Yankee Motor Corporation only had eight of the radially finned engines on hand during prototype testing.
Barry Higgins was the test rider, but there were only two Yankee 460MX prototypes built. If one-of-only-0two sounds good to you, the 1972 Yankee 460 MX should whet your appetite, Sadly, the two completed prototype Yankee 460MXs were the only Yankee motocross bikes built by the Yankee Motor Company of Schenectady, New York. Too bad, because it was a beautiful machine and could have been a success if given more time.
BIKES YOU’VE NEVER SEEN BEFORE: 1972 YANKEE 460MX SINGLE Motocross Action Magazine.
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