Kohler 12RES / 8.5RES — Oil Change Procedure

Maintenance · Engine lubrication system

For the Kohler 12RES / 8.5RES, from the Kohler operator's manual.

Applies to: Kohler 12RES, Kohler 8.5RES, Kohler CH20 engine, Kohler CH 740 engine

Procedure

1. Place the generator set master switch in the OFF position.
2. Disconnect the power to the battery charger.
3. Disconnect the engine starting battery, negative (--) lead first.
4. Remove the housing side panel.
5. Remove the oil drain hose from its clip, remove the cap, and lower the hose into a container.
6. Open the oil drain valve and allow the oil to drain completely, then close the valve.
7. Replace the cap and return the oil drain hose to its clip.
8. Remove the oil filter by rotating it counterclockwise with an oil filter wrench.
9. Clean the gasket sealing surface of the oil filter adapter.
10. Apply a light coat of clean oil to the rubber seal of the new oil filter and install it.
11. Remove the oil fill cap and fill the engine to the F mark on the dipstick (capacity 1.9 L / 2.0 qt.).
12. Reinstall the dipstick and oil fill cap.
13. Reconnect the battery, negative (--) lead last, and reconnect the battery charger.
14. Run the generator set for a minute, stop it, wait 1 minute, and recheck the oil level.
15. Check for oil leaks, fix as needed, and reinstall the housing side panel.

Full service-parts list: Kohler 12RES →, Kohler 8.5RES →

Source: Kohler operator'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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