Larry I think you will be safe with the twin cylinders. I even think Kohler has solved the engine block deal on the singles as well. It was improper tq of the bolts holding the block together that snuck through the building process I think in a china plant if I'm not mistaken. The twins are mfg'd in the USA I'm pretty sure. I also did a lot of research and actually new of first hand failure of a single engine from a co-worker but again after a lot of research pinned it down just to the singles.
I spoke to 2 different independent dealers that use's Courage engines and they both assured that the single cylinders had problems in the past but had been fixed and that they hadn't had any problems with the bigger (Twins Cylinders) engines. I personally have the 24hp Kohler and it has tons of power and tq.
