Does the YS engines, particularly the 110, actually supercharge the air into the engine? If yes, about what percentage above ambient air pressure does it introduce into the carb? If this is the case wouldn't these engines lose less HP at higher elevations than a naturally aspirated engine? Just wondering.
Thanks,
Barry

Mistake, Post instead of PM.

They are not truly supercharged. They use the downstroke of the piston to push mixture into the cylinder through the use of a double sided disc valve in the backplate.

Sort of a combination 2 stroke/4stroke set up. It works very well.