RE: Rossi 21
The Rossi 65R21 version was equipped with a ring venturi intake. Check with Just Engines to see if parts can be had. You will need the venturi, needle, spray bar, nut, and seal.
I have the manual for mine in storage away from home. I will copy the parts list if you need it and e you with it. Just let me know.
Is yours fitted with the "Turbo" plug head?
RR