Harley-Davidson XL1200 Sportster 1200 Custom, Roadster Spark Plug
GarageDex's powersports data shows the Harley-Davidson XL1200 Sportster 1200 Custom, Roadster uses a B6L spark plug, gapped to 0.040".
Spark plug fitment by year
| Years | Standard plug | Iridium upgrade | Gap |
|---|---|---|---|
| 1978-1981 | B6L | - | 0.040" |
1200cc motorcycle. Match the exact part code, thread reach, and heat range. The iridium column is the same-fit upgrade for a longer service life.
Spark plugs for your Harley-Davidson XL1200 Sportster 1200 Custom, Roadster
The recommended plug is a B6L. Match that code - spark plugs are thread-, reach-, and heat-range-specific, so the part number matters more than the brand. Gap it to spec before it goes in and you're done.
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Frequently asked
What spark plug does a Harley-Davidson XL1200 Sportster 1200 Custom, Roadster take?
GarageDex's powersports data shows the Harley-Davidson XL1200 Sportster 1200 Custom, Roadster uses a B6L spark plug, gapped to 0.040".
What is the spark plug gap on a Harley-Davidson XL1200 Sportster 1200 Custom, Roadster?
The Harley-Davidson XL1200 Sportster 1200 Custom, Roadster spark plug gap is 0.040". Set the gap with a feeler gauge before install - iridium plugs come pre-gapped but always verify, since a wrong gap causes misfires and hard starts.
How often should I change the spark plugs on a motorcycle?
Standard plugs typically want replacing every 8,000-12,000 miles (or per your service manual); iridium plugs go much longer. Fouled or worn plugs cause hard starts, misfires, and poor fuel economy - a cheap part that punches above its weight.