ENGINE REVIEW: O.S. FS-200S

PHOTOS BY PETE HALL The Big Bang model for 4-strokes The pushrod tubes are sealed at both ends with O-rings that help to supply oil to the engine's lower end. The twin-needle 80N carburetor can be rotated 180 degrees to make the engine more versatile when it's mounted in an airframe. THE RACE TO PRODUCE big-bore, single-piston 4-strokes continues. And why not? While being way more affordable than multi-cylinder designs, they are also more powerful...