What I have here is a very unique engine configuration from a Japanese Domestic 90cc(89) CL90. In Japan they were 90cc, in the USA 100cc.
Some background about 10 years ago, a good friend who is an officer of the Vintage Japanese Motorcycle Club. He is a meticulous restorer and he had a proposition , He wanted a Honda CL175K3 in Orange Model that I had available. He was willing to swap his restored Japanese Domestic CL90 for my model. In his restoration, he had changed the Japanese 90cc cylinder and head combination to the US specification 100cc model. In the trade he gave me the changeover parts. They all appear to be in good condition.
So pictured is the cylinder which the inside is very smooth, the Cylinder Head,(no valves)a brand new piston, and two sets of rings. Both sets are new, one box is stamped 13021-107-004, the other box the number can't be read.
I just discovered them in a box, and now I am willing to pass them along to someone who might need them.
So anyone with a domestic CB or CL100 that needs a new upper end--this is a really good start. You will just lose the slightest amount of displacement.
I have included a picture of the restored CL100 we swapped for your identification