Cummins/Onan 4.0BGEFA261 OOL / 4.0BGEFA26100L — Spark Plug Replacement
Maintenance · Spark plugs
For the Cummins/Onan 4.0BGEFA261 OOL / 4.0BGEFA26100L, from the Cummins/Onan operator's manual.
Applies to: Cummins/Onan EM (SN5782U1G2RA) engine
Procedure
- Refer to Table 4 for scheduled spark plug replacement; the genset has two spark plugs.
- Thread a spark plug in by hand until it seats to prevent crossthreading.
- If reusing the spark plug, turn it with a wrench an additional 1/4 turn.
- If the spark plug is new, turn it an additional 3/8 to 1/2 turn.
- If a torque wrench is used, tighten the spark plug to 8 lbs-ft (10 N-m).
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Spark plug gap 0.025 inches (0.64 mm)
- Spark plug tightening torque 8 lbs-ft (10 N-m)
- Reused plug 1/4 turn; new plug 3/8 to 1/2 turn after seating
Source: Cummins/Onan 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.