Engine and timing marks — basic information and use

1. Top dead center (TDC) is the highest point in the cylinder that each piston reaches in its stroke as the crankshaft rotates. Each piston reaches TDC at the end of the compression stroke and again at the end of the exhaust stroke. However, TDC basically refers to the position of the piston during compression. Piston No. 1 is located on the side of the camshaft drive chain.

2. Setting the piston of the 1st cylinder to the TDC position is an important condition for many procedures, such as replacing the drive chain and replacing the camshaft.

3. Determine the position of the terminal of the high-voltage wire of the 1st cylinder on the cover of the ignition distributor. If the terminal is not marked, trace the high voltage wire from the spark plug of the first cylinder to the cover (cylinder No. 1 is located on the engine side of the drive chain).

4. Remove the camshaft cover as described in paragraph 4.

5. Using a suitable socket on the vibration damper hub bolt/crankshaft pulley, turn the crankshaft clockwise until the following marks are aligned (see fig. 3.5, a, b).

• A) TDC label ("O/V) on the crankshaft pulley is aligned with the pointer on the camshaft timing chain case.
• b) The TDC notch on the flange at the front of the camshaft is aligned with the top surface of the cylinder head.
• V) The ignition distributor slider is aligned with the mark on the outer rim of the distributor housing (you may have to remove the dust cover to see the mark).

6. When the marks are aligned as described in a 5, the piston of the 1st cylinder will be in the TDC position. If the camshaft drive chain is to be removed, do not rotate the crankshaft until the chain is reinstalled.