3. INSPECTION/ADJUSTMENT GRAND DINK 125/150 Timing Hole Cap IGNITION TIMING · The CDI unit is not adjustable. · If the ignition timing is incorrect, check the ignition system, Remove the timing hole cap. "F" Mark Check the ignition timing with a timing light. When the engine is running at the specified idle speed, the ignition timing is correct if the "F" mark on the flywheel aligns with the index mark on the crankcase cover. Also use a timing light to check the advance. Raise the engine speed to 4,000rpm. The index mark should be between the advance marks. Timing Light CYLINDER COMPRESSION Warm up the engine before compression test. Remove the center cover and spark plug cap. Remove the spark plug . Insert a compression gauge. Open the throttle valve fully and push the starter button to test the compression. Compression: 152kg/cm If the compression is low, check for the Compression Gauge following: Leaky valves Valve clearance to small Leaking cylinder head gasket Worn pistons Worn piston/cylinder If the compression is high, it indicates that carbon deposits have accumulated on the combustion chamber and the piston head. 3-7