For the last few years I have toyed with the idea of building a homemade two-stroke engine for UL use. What keyed my interest was reading about homemade model aircraft engines and reading and watching a re-enactment of the Wright brother's first flight with a replica engine (not a two-stroke engine).
Has anyone made a 2-stroke engine from scratch? One may need to cast aluminium, may need a lathe and milling machine with boring head and hone or perhaps the boring and honing of the cylinder and bearing journals could be farmed out. A commercial carburetor and piston could be used. Two-stroke engines seem simple enough that home construction may be possible, if not practical.