Thats pretty wild looking. Looks pretty dangerous, too. The pic was obviously taken some time ago, as today you would have a helmet, eye protection, gloves, elbow and knee pads, etc. LOL What size engine is that?
My dad and I started on a project awhile back something like that. He bought an old Honda CB350, and we cut the three frame bars leaving just the engine in part of a cradle. We were going to weld it as is to a 1" square frame go-cart type chassis. I cut the mufflers off then reversed them, so the pipes came up and over the engine. I had the shifter linkage figured out, but never decided on a throttle linkage. I ended up losing a bunch parts while moving, and gave up on the whole thing. Woulda been cool though. Nice to see someone had one that was actually done and enjoyed!
Greg