I have a similar drain plug problem on my 5 horse Tecumseh on the "Kindalikeawhizzer" build. I find that I need to lower the engine a couple more inches,but that will make removing the drain plug either a pita or impossible. Looking at the plug Ludwig posted got me to thinking about the problem again and seeing it on the screen magically transported me to the hardware store... and I saw a possible solution for me which involves an elbow threaded in and something or other threaded to the other end of the elbow leading to a valve to drain the oil into a container. Real time in the plumbing department and staring at stuff should lead to some kind of Rube Goldberg solution. Thanks!
SB
SB