Piston ring compressor tool
Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police models
While I've always used my fingers and/or a wooden popsicle stick to compress piston rings when fitting the cylinder to the piston, you may prefer a dedicated tool. Many of the automotive tools are far too tall and unwieldy for our application. Ralf Brinkmann sent me this information in a personal e-mail. In Ralf's own words:
My 650 cc Ural with high compression pistons has very fragile oil rings. I used a ring compressor for car engines as base to build my own tool. My antique sheet-iron shears did cut the thin hardened sheet metal very easily like paper.
The tool did also work with great success on new 83 mm Guzzi pistons for the 850 cc engines.