I rode my tanaka bike for hours today. I pedaled with a social bike group, ate some tacos for dinner, then motored around through a couple tanks (1/2 gal) of gas to break the engine in and get out of the house a while. The Tanaka33 filter cover fell off. Ugh!
I suppose I will have to purchase another, or figure out a substitute.
Edit: I made a whole filter box from a snuff can and foam . Nothing new to the world, but good enough for small engines.
Scott O has posted links to Daves Motor Sports which has all the relevant replacement parts like velocity stacks, filters, and filter boxes.
Thread about our findings.