DLE40 engine

This model is based on https://grabcad.com/library/dle-40-gas-engine-with-starter-1 The above model, in SolidWorks format, misses some parts and doesn't provide neutral file format like STEP. Also, the above model by Guy Alea seems to represent an older version of the engine with taller cylinders than current engine has. I didn't update the cylinders, but verified that all other important dimensions, like the mounting hole positions and the distance between the back plate and the prop hub are correct.