The Strato is similar to Echos Tornado. They use a 2 barrel carb with the upper barrel being air only. It feeds via external tubes to the outside of the upper tranfers ports, both entry ports using a reed valve. These feeds begin the flush of exhaust gases so the fresh air/fuel charge can be better timed and losing less fuel out the exhaust in the exchange.
The reduction of un-burned fuel out the exhaust and the resulting poor burning of that fuel in the muffler has improved emissions output.
Down side is it also means less fuel pumping through the combustion chamber to aid in cooling so more care then ever is needed in supplying the engine with good fuel/oil quality and ratio's.
