The Space Hopper was Cox's first attempt at a beam mount high performance reed valve engine plus the first steps towards their greatest engine, the Tee Dee series. The engine was basically like the Thermal Hopper was to a Space Bug. That is a Babe Bee without a tank, but a venturi and needle valve relying on an external fuel tank. The engine looks similar to the Sportsman engine with a machined aluminum crankcase and rear induction via a reed valve with the needle valve assembly and venturi similar in appearance to the later Tee Dee series. This engine was short lived and made way for the Tee Dee in 1960. Due to their similarities to the Tee Dee that followed some of the parts crossed over from this engine to the Tee Dee. They look very retro and due to their apparent rareness are worth around 200 US dollars in 2008.