The Triumph Speed Triple 1200 RS uses a NGK LMAR9E-J spark plug. A worn plug causes hard starting, rough idle, and poor fuel economy — and it’s one of the cheapest parts on the bike to replace.
Inspect the plug every service and replace it at the factory interval or sooner if the electrodes look rounded or the insulator is heavily discolored.
Triumph Speed Triple 1200 RS quick service specs
| Item | Specification |
|---|---|
| Engine oil | 10W/40 or 10W/50 semi or fully synthetic, API SH (or higher), JASO MA (e.g. Castrol Power 1 Racing 4T 10W-40) |
| Oil capacity | 3.3 liters |
| Oil change interval | 10000 miles |
| Chain slack | 32-42 mm |
| Spark plug | NGK LMAR9E-J |
| Tire pressure (F/R) | 34 PSI front / 42 PSI rear |
| Battery | HJTZ14S-FPZ (LiFePO4 lithium-ion), 12V 8Ah |
How to replace the spark plug, step by step
- Let the engine cool completely. Remove the seat/tank panels as needed to reach the plug cap on the cylinder head.
- Pull the plug cap straight off. Blow any dirt away from the plug well with compressed air so nothing falls into the cylinder.
- Remove the plug with a spark plug socket. Note how far it was threaded in.
- Check the gap on the new plug with a feeler gauge and set it to the spec in your owner’s manual.
- Thread the new plug in by hand first to avoid cross-threading, then torque to spec (or snug plus the turn specified on the plug box).
- Reinstall the plug cap firmly and refit any bodywork.
Common mistakes to avoid
- Cross-threading the plug — always start it by hand.
- Over-torquing — aluminum heads strip easily; use a torque wrench.
- Skipping the gap check — plugs don’t always come pre-gapped for your bike.
FAQ
What spark plug does the Triumph Speed Triple 1200 RS take?
A NGK LMAR9E-J. Stick with the stock heat range unless you have a specific, well-understood reason to change it.
Can I use iridium plugs?
Yes — iridium lasts longer and fires a bit more consistently, but gap it to the same spec as stock.
What does a fouled plug look like?
Wet black deposits mean rich running or oil; dry sooty black means rich mixture or weak spark; white blistered means too hot/lean.
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Dan Heiman
Writer at Helmet Today, covering helmet reviews, fit and riding safety.
