Hopefully this question hasn't been asked TOO many times, but I was hoping you guys could clear this up for me.

I know that for most 4 strokes to be run inverted successfully, the centerline of the fuel tank should be at level or lower than the carb of the engine.

However, I've also heard that since YS engines have a built-in pump, they don't have this requirement. Is this true? I'm sort of deciding between a YS63S and a Saito 62, and this might be a decision-maker. Thanks.