RE: Inverted Engine
Four strokes don't seem to suffer any running problems being inverted. The scale cooling air exit is generally in the bottom of the cowl, this allows better cooling air ventilation to the cylinder when the engine is inverted. However, with baffles in the engine compartment the engine can be adequately cooled in any position. From a personal point of view I will opt for side mounting, head to the right if at all possible for both 2 & 4 strokes. Others will invert anything and tell you it works fine. I've been doing this since 1968 and my experience just tells me my way positively works every time, so I stick with it.