911 SC Cabriolet F6-2994cc 3.0L SOHC (1983)
Beginning with No.1 cylinder the crankshaft and belt pulley should be turned to the right until both valves of No.1 cylinder are closed, and the
cylinder TDC marking (Z1) on the belt pulley coincides with the mark on the crankcase.
Proceed as follows:
1. Remove cylinder head cover.
2. Bring piston of cylinder to be adjusted to TDC on firing cycle.
3. Check valve clearance with feeler gauge.