Motorcycle Repair: Pistons CB77E, 1964, piston ring set, kawasaki kz550

Question
I have got a Honda CB77E 1964, prepared for Classic Racing, with oversized 64 mm (347 cc) pistons.
I need pistonrings but I can't identify the manufacturer. Can't get information from the earlier owner.
The pistons is marked in the bottom with a composed "-AE- 18551" and "AM 413", on the top is "ID66 STD A" have cylinderic rings about 1 mm deep and about 5 mm in between, all the way from top to bottom. There is also a big cut out on both side of the piston skirt (bottom).
(Might be Am. Norris pistons?)

Regards/Kuno from Sweden

Answer
Kuno, are the pistons forgings or cast manufacture? There are Italian race pistons available in the UK that use CB350 twin piston rings, but I don't know the exact ring widths. Honda pistons usually are marked ART and are castings. STD CB350 pistons are 63mm, so a 1.00 overbore piston/ring set may work. Honda first generation XL175s were also 63mm in STD bore size, with Honda offering the 1.00mm overbore.

WEBCO pistons used DYKES rings which are L shaped in cross section. They could be some kind of oversized CB750 racing pistons, too that came from numerous suppliers back in the 1970s. SOHC CB750s were 61mm.

Check with WISECO pistons in the US, or Venolia, perhaps. When I was trying to get someone to make up some 64mm pistons, that was about as small as they could do, automotive wise. I think they fit a FIAT or something like that.

Some engines have been modified with Kawasaki KZ550 or 650 pistons, too.

I don't recognize what you have described, unfortunately.

Bill Silver