A sample from the products for the Crankshaft/piston include: Pl,oil Through, B/brg Rad N/com, Nut,hub, Ring Set,piston,0.
The most reasonably priced component used on the Cb250 Nighthawk 1991 (m) Mexico / Kph Crankshaft/piston is the Screw Flat 6x16.
On this parts fiche the Bolt,flange,8x35 is the most specified component.