Above on the page there are several PDF Owner's Manuals for ATK Motorcycles.
Originally ATK specialized only in four-stroke engines. But customers were literally dreaming of two-stroke motorcycles, so Horst Leitner put the Rotax 406cc engine in a four-stroke frame.
The success of his frame kits caught the attention of owner Puch, who turned to Horst with the idea of creating a new motorcycle brand.
The Puch name has been well known in the motorcycle industry since the Austrian company won the 1975 World Motocross Championship.
Leitner jumped at the idea because Puch had promised him everything he needed to build a motorcycle, including access to Rotax four-stroke engines.
It was the push that eventually led Horst to develop and create his own brand - ATK (Anti-Chain Tension), and at one point he was the sixth largest off-road motorcycle brand in America.
After a successful debut, Horst decided it was time to try his hand at making a full motorcycle.
The first ATK prototype used a four-stroke 562 cc engine from the Austrian manufacturer Rotax, coupled with a White Power suspension.
It was a revolutionary machine for its time.
The reaction to the initial prototype was so overwhelming that Leitner set about making his dream come true - the production of ATK motorcycles.
The first four-stroke models ATK 560 and ATK 604 / 605 were instant hits.
And each of their customers was convinced that the four-stroke engine is the engine of the future. And mind you, this was ten years before Yamaha's first YZ400 prototype was unveiled.
When Bombardier approached Horst in 1988 with a proposal to build a prototype two-stroke engine to replace the aging Can-Am off-road motorcycle fleet, he created one of the world's most unique off-road motorcycles of all time, the ATK 406 two-stroke.
It was destined to be the new Can-Am as the Bombardier plant no longer wanted to run a motorcycle assembly line in Canada.
Over a seven-year period (1989-1995), sales of the ATK 605 four-stroke and ATK 406 two-stroke made ATK the sixth largest off-road motorcycle company in America.
ATK motorcycles will be manufactured for another ten years at Horst's small workshop in Laguna Beach, California (and later at the Commerce, California plant).
If the Can-Am dealer network hadn't decided to fund the production of the ATK 406 to save their dealerships, ATK would never have had such economies of scale.
He ultimately decided to sell ATK Motorcycles to a conglomerate, which moved the plant to Utah.