What is the difference between the Tecumseh HM80 small engine and the Tecumseh HMSK80 small engine?

HM80 stands for horizontal medium-frame 8 HP and HMSK80 stands for horizontal medium-frame Snow King(in other Word a snowthrower engine) generally equipped with a looped starter grip for mittened hands, intake system that resists icing and possibly an electric starter that uses household current.