High-performance 10mm spark plug wires engineered as a direct replacement for Harley-Davidson Softail models FXST/FLST from 1984 to 1999. Key benefits - Restores reliable ignition: replaces worn or cracked wires to eliminate misfires, rough idle, and inconsistent starts. - Built for street and race use: 10mm construction supports both daily riding and higher-demand track or spirited riding conditions. - Saves installation time: perfect fitment and direct-replacement design mean plug-and-play installation with no modifications required. - Long-lasting reliability: made from high-quality materials for durable performance and consistent operation over time. What it is - Product: 10mm high-performance spark plug wires - Compatibility: Harley Softail 1984–1999, models FXST and FLST - Wire length: 17" / 7" (two lengths included to suit routing needs) - Fitment: direct replacement, designed to match factory routing and connectors How it solves problems - Eliminates ignition-related drivability issues caused by degraded wires. - Provides consistent spark delivery under varying loads and RPM, reducing hesitation and improving throttle response. - Durable construction reduces the need for frequent replacements and maintenance. Practical use scenarios - Routine maintenance: replace age-worn wires on a 1988 FXST to restore smooth idle and reliable cold starts. - Performance weekend or track day: install the 10mm wires before a track event to ensure consistent spark delivery under higher engine stress. - Restoration project: use as a direct-fit upgrade when rebuilding a 1995 FLST to maintain correct routing and plug spacing. Installation notes - Direct-replacement design matches stock routing and connector spacing; verify wire lengths (17" and 7") fit your routing before final installation. - No special tools required beyond typical hand tools used for spark plug access. Quality and compatibility - Designed specifically for Harley Softail FXST/FLST models from 1984 through 1999. - Built from high-quality materials for dependable, durable performance consistent with the original specifications.