50 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 A, B, or C; A-30mph, B-25mph, C-20mph.
- 1980 and up they reversed the coding; 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 mph serie 40 and series 50 Moby.