So, does anyone know the differences between the different speed versions (20, 25, 30 mph) of the batavus mopeds. The only difference I can find is different jet sizes (52 for 20mph, 54 for 25mph etc.) So, by this logic, I should be able to turn a 20mph moped into a 30mph moped simply by upping the jet size to a 56 or 58. Is this true? Any help is very much appreciated.