Setting the piston of the first cylinder to TDC on the compression stroke is an essential part of the process of replacing the pulleys and timing belt, as well as adjusting the valve clearance.
To set the piston to TDC, it is necessary to turn the crankshaft clockwise when looking at the engine from the side of the toothed belt. Turn the crankshaft with a wrench on the central bolt securing the pulley to the crankshaft.
Attention! Before setting the piston of the first cylinder to TDC, turn off the ignition and set the gear lever to the neutral position.
Install the piston of the first cylinder at TDC in the following order:
- turn off the ignition system by disconnecting the electrical connector from the ignition unit;
- unscrew the spark plugs and install the tip of the compression tester in the hole for the spark plug of the first cylinder;
- turn the crankshaft clockwise and as the piston of the first cylinder approaches TDC, the compression gauge will begin to show an increase in pressure in the cylinder. Continue turning the crankshaft until the mark on the vibration damper aligns with the TDC mark on the front cover (pic. 3.1).
Pic. 3.1. Alignment of the mark on the vibration damper with the TDC sign on the front cover
After setting the piston of the first cylinder to TDC in the compression stroke, turning the crankshaft by 180°, you can set the remaining pistons to TDC in the sequence corresponding to the order of operation of the cylinders.