gwest_ca-(File Mod) 10,513 #26 Posted August 7, 2023 Anyone familiar with the model L Gravely tractors know the the exhaust valve stem will seize in the guide if MMO is not added to the fuel. 2-cycle oil also works. Often wonder if eliminating lead in the fuel is the cause of it. To my way of thinking the Kohler valve springs are weak so the valves may not close fast enough or 100% close and the MMO lube on the valve stem is just enough to help. 2 Share this post Link to post Share on other sites
