Jet Valve Adjustment
- Before adjusting, note the following:
- Misadjusted jet valve clearance will adversely affect emission levels.
- Adjust jet valve clearance before adjusting intake valve clearance.
- Before adjusting jet valve, retighten cylinder head bolts (cold) to 65-72 ft. lbs. (88-98 N.m) on all engines (bolt Nos. 1-10 on Starion Turbo). Tighten bolt No. 11 to 11-15 ft. lbs. (15-20 N.m) on Starion Turbo.
- Adjust jet valve clearance with intake valve adjusting screw fully loosened.
- With engine at normal operating temperature, stop engine, remove rocker cover and position appropriate piston at TDC of compression stroke.
- Back off intake valve side adjusting screw 2 or more turns. Loosen lock nut on jet valve adjusting screw.
- Back off jet valve adjusting screw (counterclockwise) and place .006" (.15 mm) feeler gauge between top end of jet valve stem and bottom end of adjusting screw. See Fig 1 .
- Turn down adjusting screw (clockwise) until proper clearance is obtained. Tensile strength of jet valve spring is weak. DO NOT force screw to turn, putting excess pressure on spring.
- Hold adjusting screw and tighten lock nut. Recheck clearance. Adjust intake valve clearance to .006" (.15 mm). Repeat adjustment at each cylinder.