Sierra 18-5187 Ignition Coil kit Direct OEM replacement Mercury-Mercruiser 339-856991A-1 Ignition Coil

Sierra 18-5187 Ignition Coil kit Direct OEM replacement Mercury-Mercruiser 339-856991A-1 Ignition Coil

The Sierra 18-5187 is a high-performance aftermarket ignition coil engineered as a direct replacement for Mercury/Mariner and Chrysler/Force outboards. Meets or exceeds OEM specifications in fit, function, and durability. Built with marine-grade epoxy and brass internals, it delivers reliable, high-energy spark for smooth starts, strong acceleration, and consistent performance in harsh saltwater and freshwater environments—perfect for cost-effective repairs and upgrades.

Quick Specs:

• Sierra high-quality engine parts are designed to meet OEM specifications.

  • For Mariner 200 DFI, 225 DFI, V135 DFI (2.5L), V150DFI (2.5L)
  • For Mercury 3.0 DFI

  Interchangeable with:

  • Mallory
    • 9-23201
  • Mercury Marine
    • 339-856991A1
    • 339-850227
  • Mercury Race Outboard
    • 339-856991A1
  • Mercury Sport Jet
    • 339-856991A1

Special Order Item: Allow 3–7 business days for processing and delivery. Contact us to confirm availability and place your order – we'll handle the rest for reliable, OEM-quality performance.

Pro Tip: Test your stator before install to avoid failures.