New to all this so dont shoot me down please. I have bought a boat with an old 100 hp jono and I want to upgrade to a newer engine. I've been looking and i've seen things like "90hp XL shaft" or "90hp 20"leg". Where are the legs meeasured from? Need to know what i have and what i need. Should i sell my motor complete with steering, wiring ect or will I be better off keeping it with the boat? Thanks in advance, Steve