Jan, you call it desigh flaws. I would not! Saito twin engines are/were also known for cylinders cutting out. So are Seidel radials. Design flaws or user ignorance? Sometimes all it take is using different plugs L/R. My OS15 4S also needed glow support near idle. Design flaw? Come on and give me a break!

After the take-over into private hands MVVS assembled these engines as long as parts were available. With all parts gone they stopped selling them because they were not part of their new ideology in which there was no room for niche market engines.