Chuck,
The only bad thing about the sachs engine is that its one piece.... you can't mill the head or space up the cylinder.
It is interesting to note that there is a huge difference between the very small crank case transfers and the large transfers on the cylinder.
I have an extra bing carb for the sachs, complete except without the main jet. If you are interested its $40. I don't have the air filter.
wilsom@rpi.edu