Harley-Davidson FLSTF Softail Fatboy Spark Plug
GarageDex's powersports data shows the Harley-Davidson FLSTF Softail Fatboy uses a DCPR7E spark plug, gapped to 0.040", or upgrade to the DCPR7EIX iridium plug.
Spark plug fitment by year
| Years | Standard plug | Iridium upgrade | Gap |
|---|---|---|---|
| 2007 | DCPR7E | DCPR7EIX | 0.040" |
1586cc 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 FLSTF Softail Fatboy
The recommended plug is a DCPR7E. Match that code - spark plugs are thread-, reach-, and heat-range-specific, so the part number matters more than the brand. Worth considering: the DCPR7EIX iridium upgrade - it fits the same port, fires cleaner, and lasts far longer between changes.
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Frequently asked
What spark plug does a Harley-Davidson FLSTF Softail Fatboy take?
GarageDex's powersports data shows the Harley-Davidson FLSTF Softail Fatboy uses a DCPR7E spark plug, gapped to 0.040", or upgrade to the DCPR7EIX iridium plug.
What is the spark plug gap on a Harley-Davidson FLSTF Softail Fatboy?
The Harley-Davidson FLSTF Softail Fatboy 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.
Are iridium spark plugs worth it on a Harley-Davidson FLSTF Softail Fatboy?
The DCPR7EIX is the iridium upgrade for the standard DCPR7E. It fits the same port and heat range, fires more reliably, and lasts far longer between changes - a worthwhile swap for most riders, though the standard plug is perfectly fine if you change plugs on schedule.
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.