Cummins/Onan E125 / E140 — Adjusting Valve Lash
Adjustments · Valve Rocker Assembly
For the Cummins/Onan E125 / E140, from the Cummins/Onan service manual.
Applies to: Cummins/Onan E125, Cummins/Onan E140, Cummins/Onan E125H/E140H engine
Procedure
- Engine must be at room temperature.
- Remove the valve rocker cover and spark plug.
- Turn engine over until piston is at COMPRESSION TOP DEAD CENTER.
- Check intake and exhaust valve lash with a feeler gauge.
- Loosen locknut and turn lash adjusting screw until specified lash obtained.
- Tighten locknut and recheck lash.
Tools required
- feeler gauge Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Intake and exhaust valve lash 0.15-0.25 mm
- Valve Lash Adjusting Nut M7: 7-11 N-m
Source: Cummins/Onan service 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.