Still having fun
With the new oil's you should be able to run the 36 or 40:1 no sweat. I use an NGK B6H and run 50:1 but be careful, I also have taken the engine apart two times and honed the high spots off the piston. The piston from an expensive motorcycle has taper in them, these do not. With a chrome cylinder there is not much chance of it breaking in fast, or at all. it is too bad that these engines use a weed whacker wrist pin size, 80cc and that pin, please. It is a miracle these engines last at all. GruBee was putting together a good engine at about the time the EPA put these engines on the list, too bad it would have been nice. I am saving my Duckets for a Whizzer kit, but it is fun to see what these things will do. Have fun, Dave