After many hours of frustration of mounting 80cc engine to a brandnew standard Huffy single speed cruiser with failed attempts to get the 415 chain from hitting tire, I finally decided to take a serious look at the mounting holes in the engine. Namely the rear mounting holes for the seat tube
It appears the drilled and tapped holes, much like every other 'machined' metal part including the rubber rag joints holes and sprocket kit clamps, are misaligned. I suspect, the Chinese manufacture relies on arm length visual hole alignment for drilling and the day my kit was made, they had some myopic person doing the drilling. So, using the handy putty epoxy, I filled in the 2 engine mount holes and redrilled and tapped and was able to move the mount over nearly a full 1/4" just enough clearance to clear the tire. The aluminum casting on the block is about 3/4" thick solid it appears in that area. Next, I'm taking off the rear sprocket and rag joint and clamps and redrilling them so they all line up.
Also, good idea to boat anchor the locking nuts on the rear sprocket and go with standard lock washer arrangement so sprocket can be hand tightened before carefully star patterning the tension. I also took the sprocket to a machine shop and had him enlarge the center hole to perfectly fit the hub dust cover. The 44 tooth sprocket fits perfectly in a 3 jaw lathe for that purpose.