I was watching a video last night of a guy stripping down a RG400 (same as 500) square 4 with rotary valves. Is there any advantage of one over the other (reed) in terms of power and efficiency ? Those carbs hanging of the side looked pretty nice but makes airbox design and fuel delivery quite tricky I think especially on a 4 cylinder. The double crankshafts with opposite piston moving together was a thing of beauty 
