Here ya go kids;
The Keystone Mini Bike was invented in 1968 and produced until 1971. The Mini Bikes were made in Naroshino City, Chiba Prefecture Japan by Tanaka Kougyo Company (manufacturer of small engine products including, gas weed eaters, hedge trimmers, chainsaws, generators etc). The engine is from a power rickshaw, the bike was designed by Keystone Canada 7 USA, a company that specialized in the manufacturing of custom car wheels. There were two models available, the standard Keystone basic yellow model and the deluxe model (red and black) that incorporated front springs, a chain guard and a chrome exhaust. Later models came with a chrome swept exhaust and folding foot pegs. There were accessories packages that included special sprockets and an expansion chamber exhaust system. Total production of both models were approximately 23,000 units.
Two 4-cycle models were also produced utilizing a Tecumseh engine with a cyntriphical clutch.
From this excellent resource;
https://jleibovitch.tripod.com/id113.htm