they have a different number of teeth to match the different starters, if you want to switch to a 12V starter, you'll need to change the ring gear or find a later flywheel .... use 12V on the original 6V starter and you'll be fine
"When we tug a single thing in nature, we find it attached to the rest of the world" ~ John Muir "When we tug a single thing on an old truck, we find it falls off" ~ me Some TF series details & TF heater pics
