I have a 2012 CVO Street Glide which is a FLHXSE3.
A FLHXSE2 is a 2010 year model.
A FLHXSE4 is a 2013 year model.
Not sure as what you mean "Screaming Eagle 3???
the numerical designation is usually the release of that model. for example, in 2012 they came out with the screamin eagle road glide custom, fltrxse. in 2013, they had the second iteration of that model, fltrxse2.
Whats the difference tween a screaming eagle ultra and screaming eagle3
Newbie here havent quite figured it out yet
Hi from the UK and welcome to HDF. The bikes you are referring to are collectively known as the CVO models (Custom Vehicle Operations, or something close to that!). We actually have a separate CVO section, where you may learn more.