Re: motorized bicycle throttle
I should elaborate,
The first kit I did was for a customer, he didn't do anything to the throttle handle, just attached it! of course it didn't fit! Which was good for him, because he would have had major problems with the rest of the install anyway.
I looked through the manual that came with his kit from Bike-to-moped...considering these kits usually come with nothing, the bike-to-moped instructions weren't that bad.
There was no mention of the protrusion on the throttle handle casing. I immediately figured that it was designed to fit in a hole in the handle bars so that the throttle would not be able to slip rotationally or laterally.