Tecumseh 8 HP Hm80-155444p Horizontal Shaft Engine UsedTECUMSEH 8 HP HM80-155444P HORIZONTAL SHAFT ENGINE USED. Good engine, runs with gas sprayed into carb, may need tune up/carb work. Crankshaft is 3 3/8″ long and is stepped-1st 1 5/8″ is 1 3/8″ wide, next 1/2″ is 1″ wide and final 1 1/8″ is 7/8 wide..