Cummins/Onan GTA8.3 / GTAB.3 — Spark Plug Removal
Maintenance · Ignition system
For the Cummins/Onan GTA8.3 / GTAB.3, from the Cummins/Onan owner's manual.
Applies to: Cummins/Onan GTA8.3 engine
Before you start
- Be careful not to drop the spark plug.
Procedure
- Disconnect wires from ignition coil end first, then spark plug end.
- Remove rubber insert from spark plug socket to prevent contamination.
- Loosen spark plug with 5/8 in deep-well rubber insert spark plug socket.
- Slip 3/8 inch inside diameter hose over plug end and turn counterclockwise.
- Lift spark plug out and mark with cylinder number.
- Visually inspect plug wires, extenders and connections for damage.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
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.