Cummins/Onan — Overhead Set - Adjust Valves and Injectors (STC)

Adjustments · Valve Train

From a Cummins/Onan owner's manual covering: M11, M1i Series Engines, ps200da. Check it applies to your exact model before use.

Applies to: Cummins/Onan M11 engine

Procedure

1. Remove the crankcase breather tube from the crankcase breather outlet.
2. Remove the 16 capscrews, isolators, and spacers from the cover.
3. Remove the rocker lever cover and gasket.
4. Rotate the accessory drive shaft clockwise until the A valve set mark aligns with the pointer.
5. Loosen the injector adjusting screw locknut and tighten the adjusting screw until clearance is removed; then one additional turn to seat the link.
6. Loosen the adjusting screw until the STC tappet touches the top-cap of the injector.
7. Place the STC tappet adjusting tool, Part No. 3823348, on the top-cap and insert the locating pin.
8. Apply thumb pressure to hold the tappet in the maximum upward position.
9. Use torque wrench, Part No. 3376592, to tighten the adjusting screw to 0.6 to 0.7 Nm [5 to 6 in-lb].
10. Hold the adjusting screw and tighten the locknut to 61 Nm [45 ft-lb] without adapter or 47 Nm [35 ft-lb] with adapter ST-669.
11. Remove the tappet adjusting tool and check the injector push rod can be rotated by hand.
12. Adjust the valves on the appropriate cylinder with a feeler gauge per the sequence chart.
13. Tighten the valve adjusting screw and locknut, then check lash with a feeler gauge.
14. Install the cover, 16 isolators, spacers and capscrews; tighten to 15 Nm [130 in-lb].

Source: Cummins/Onan owner's manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.

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