As for gearing ratios, I gear it between 17/73 and 17/65 for JB (#219 chain). Next season he moves up to JA and I’m getting a 19T clutch sprocket so he can get up to higher speeds with the same axle sprockets.
Hmmm… So, if I just simply swap the carb slides, one of the kids is going to be at a disadvantage. That sucks. I hadn’t considered that. Argh…. My daughter turns 12 in May, so she can run JB until then. I need to research that age/class rule again.
As far as sticking with #35 (what’s on the KT100 now) or switching to #219.
Drive sprockets come with the World Formula
Axle sprocket set $100
Use chain I have
Drive sprocket set $45
Axle sprocket set $90
Note: These are approximate values on economy units.
So, it’s close to a wash. I’m going to go with a new #219 setup.