50V Speed Categories
From Moped Wiki
- 1970 to 1978 it was marked on the steering head tag on US models 20mph 25mph or 30mph.
- 1978 and 1979 it was coded on the steering head tag ABorC A-30mph B-25mph C-20mph
- 1980 and up they reversed the coding of ABorC tp A-20mph B-25mph C-30mph
More then just the cylinder makes a AV7 a fast or slow machine so I attached a list of things which make a difference between a 20 - 25 - 30 mpy serie 40 and serie 50 Moby.