The CRM 50 typically uses a Keihin PF70 (18mm) carburetor. If the bike is bogging, check the #108 main jet or adjust the pilot screw (standard setting is usually 2.5 turns out ).
For an exploded view of all components, the Bike-Parts-Honda site provides detailed diagrams and part numbers for various model years. honda crm 50 manual
Because these bikes are now over two decades old, they require a hands-on approach to ownership. The dealership support that once existed has largely faded, leaving the as the only bridge between a rider and a running motorcycle. The CRM 50 typically uses a Keihin PF70 (18mm) carburetor
SAE 10W-30 (standard for small Honda 2-strokes) honda crm 50 manual
Because this manual is rare in English, owners often look to Japanese auction sites or specialty importers: