How to adjust the timing belt if it is too tight?

The timing belt can be adjusted with the hexagon key. When the belt is pressed, when the tightness is 10mm, it can turn over 90 degrees, and the engine runs normally without abnormal noise, which is the best tightness. Check the timing belt as follows: 1. Disconnect the negative battery cable first, and then disconnect the positive battery cable. 2. Disconnect the wire plug of the alternator, and then remove the engine wire harness from the cylinder head, and remove the cylinder head cover. 3. Remove the timing belt upper cover. 4. Turn the crankshaft pulley counterclockwise, and check whether the belt has cracks or oil and coolant stains, and if so, thoroughly remove them; Check the belt tooth profile for wear and replace it if necessary.