1. Disconnect the vacuum advance control hoses and plug them.
2. Connect the stoboscope according to the manufacturer's instructions.
3. Start the engine and increase the speed to 2500 rpm. In the viewing window between the block and the flywheel housing, the marking should be visible "T". If the markings are not visible, there is a malfunction in the centrifugal regulator. The inspection window is located under the distributor and is plugged with a plug.