Tecumseh later came out with non adjustable EPA carbs. That was the end for Tecumseh. They never ran well on those carbs. You can buy Chinese carbs of Amazon that have high and low speed mixture screws. It makes a huge difference. Tecumseh engines are known to freeze up the governor in winter and the engine will rev high. The connecting rod generally comes out the engine block. Tecumseh connecting rods cant take much abuse.