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Mazda Trucks 1972-1986 Repair Guide

Valve Lash



  1. Run the engine until normal operating temperature is reached.
  3. Shut off the engine and remove the rocker cover.
  5. Torque the cylinder head bolts to their specified torque, in the proper sequence.
  7. Rotate the crankshaft so that the No. 1 cylinder (front) is in the firing position. This can be determined by loosening the No. 1 injection pipe at the injection pump. When the engine is slowly cranked, fuel will squirt from the loosened fitting as No. 1 piston approaches TDC. Confirm TDC by the timing mark alignment.
  9. Check the valve clearances by inserting a flat feeler gauge between the end of the valve stem and the rocker arm. The clearance can be checked for No. 1 and No. 2 intake valves and No. 1 and No. 3 exhaust valves.
  11. If the valve clearance is incorrect, loosen the adjusting screw locknut and adjust the clearance by turning the adjusting screw with the feeler blade inserted. Hold the adjusting screw in the correct position and tighten the locknut.
  13. Rotate the crankshaft (in the normal direction of rotation), until No. 4 piston is at TDC compression. Adjust No. 3 and No. 4 intake valves and No. 2 and No. 4 exhaust valves.
  15. Install the rocker arm cover and torque the nuts to 18 inch lbs.