The R 1300 GS runs four spark plugs — two per cylinder — and BMW lists them as a routine service item. Fresh plugs restore a crisp idle, easy cold starts, and full power; worn ones cause rough running and poor fuel economy long before they fail outright.
This guide shows you how to change all four in about an hour with basic tools. The torque values and plug spec are in the table below.
BMW R 1300 GS quick service specs
| Item | Spec / Interval |
|---|---|
| Engine oil | SAE 5W-40 (API SL, JASO MA2; BMW Motorrad ADVANTEC Ultimate) |
| Oil capacity | 5.0 liters |
| Oil change interval | 6000 miles |
| Chain slack | See owner’s manual |
| Spark plug | NGK LMAR8AI-10 |
| Tire pressure (F/R) | 36 PSI front / 42 PSI rear |
| Battery | 12V 10Ah lithium-ion |
How to replace the spark plugs
- Remove the seat and side panels, then disconnect the battery negative lead.
- Unplug the stick coils and remove them, noting which cylinder each came from.
- Blow any grit out of the plug wells with compressed air.
- Remove the old plugs with a spark-plug socket and extension.
- Check the gap on the new NGK LMAR8AI-10 plugs — 0.8 mm — and fit them by hand first to avoid cross-threading.
- Tighten with a torque wrench to 12 Nm, then refit the coils.
- Reconnect the battery, start the engine, and check for a smooth idle.
Common mistakes to avoid
- Cross-threading a plug by starting it with a wrench instead of by hand.
- Over-tightening, which can damage the cylinder-head threads.
- Mixing up the coils between cylinders.
FAQ
What spark plug does the BMW R 1300 GS use?
A NGK LMAR8AI-10. Stick with the stock heat range unless you have a specific, well-understood reason to change it.
How often should I change the spark plugs?
Every 12000 miles, or sooner if the bike is hard to start or idles roughly.
Do I need to replace all four at once?
Yes — replace them as a set so all cylinders fire evenly.
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Dan Heiman
Writer at Helmet Today, covering helmet reviews, fit and riding safety.
