I was down in the "stretch cruiser " section earlier and came across the new build a fella had done with a Loncin engine installed. I went to a site suggested and to say the least, look good. I am guessing they are four stroke?? did not see but really does not matter but I like them. It would work great on my homebuilt recumbent trike just great with a J- shaft arrangement or what ever. More study to do. You guys like those engines? They are all over the place it seems. I like the low design of the things. 
