ARMY TM 9-2815-260-24 AIR FORCE TO 38G1-126-2 MARINE CORPS TM 09244A/09245A-24 5-105 b.     Repair. NOTE The following procedure is provided for repairing the cylinder head.   Remove cylinder head (refer to paragraph 4.7.4. step a.) and place on a suitable workbench. (1) Inspect valve springs as follows: (a) Inspect valve springs for alignment, wear, and damage.  Replace all defective valve springs. (b) Put valve springs on flat surface to insure that valve springs are square and parallel.   Replace all defective valve springs. (c) Measure valve spring free length.  Free length of valve spring should be 2.125 in. (54.4 mm).  Replace valve spring if not within specifications. (d) Test valve spring tension with spring compression tester (DO1168AA).  Replace valve spring if not within specifications. 1 At 1.81 in. (46.0 mm) height, valve spring tension should be 54 - 62 lb-force (240 - 280 N). 2 At 1.36 in. (34.5 mm) height, valve spring tension should be 133 - 153 lb-force (590 - 680 N). (2) Inspect valve rotators to insure that valve rotators turn freely in both directions.  Replace if defective. (3) Clean, inspect, and measure valves as follows: __________ WARNING When using bench grinder, eye protection must be worn to prevent particles from entering eyes.  Failure to comply could result in serious eye damage or blindness. CAUTION Do not use wire wheel on plated portion of valve stem.  Failure to comply could result in damage to valve and valve guide. (a) Remove all carbon from valve head, face, and unplated portion of valve stem using a soft wire wheel on a bench grinder. (b) Polish valve stem with steel wool or crocus cloth to remove any scratch marks left by wire brush.