Two Stroke Engines

I was walking back from Heaton's automotive yesterday after I dropped my truck off for an oil change and I came across a dealer in used off road toys, ATV's and motorcycles. He had several machines parked outside by the street and several of them had two stroke engines, as evidenced by the expansion chamber exhaust pipes. Everything these days uses four stroke engines, except for really small stuff like weed wackers and chain saws, so these must all be from a previous era. One ATV was notable because it had a two cylinder engine with symmetrical expansion chambers, one on each side. The engine was also set back in the frame to allow room for a portion of the expansion chambers in front of the engine. Very odd.