How to adjust the valve clearance?

There are two methods to adjust the valve clearance: cylinder by cylinder adjustment and twice adjustment. Cylinder-by-cylinder adjustment method is to determine the top dead center position of the piston in compression according to the ignition sequence of the cylinders, then adjust the intake and exhaust valve clearance of one cylinder, and then crank the crankshaft, and gradually adjust the valve clearance of each cylinder according to this method. The second adjustment method is to rotate the crankshaft, so that the piston of the first cylinder is at the compression top dead center, and the flywheel mark is aligned with the inspection hole. At this time, you can adjust the engine valve, turn the crankshaft once, so that the piston of the sixth cylinder is at the compression top dead center, and then adjust other valves. When adjusting, while tightening the adjusting screw, insert the thickness gauge between the valve stem end and the rocker arm and pull it back and forth to feel slight resistance.