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Sierra 18-99415 CDM Ignition Trigger for Mercury/Mariner 4-Cylinder 2-Stroke Outboard

Manufacturer

Sierra

<p>For nearly six decades, Sierra has established itself as one of the marine industry's most trusted names in aftermarket engine and drive parts. Founded as a specialized marine parts manufacturer, Sierra has grown into a comprehensive supplier of replacement components, instrumentation, and accessories for both recreational and commercial boating applications. Operating from their 300,000-square-foot distribution center in Litchfield, Illinois, Sierra serves boat owners and marine technicians worldwide with an extensive catalog of parts engineered specifically for the harsh saltwater environment.</p><h3>Marine Engine Excellence</h3><p>Sierra's reputation was built on delivering precision-engineered internal engine components and drive system parts that meet or exceed OEM specifications. Their <a href="/7570-sierra-engine-gasket-set-5404">engine gasket sets</a> provide critical sealing solutions for inboard and outboard motors, while their <a href="/7570-sierra-engine-complete-assembly-15341">engine complete assemblies</a> offer comprehensive replacement options for major overhauls. Each component undergoes rigorous testing to ensure reliability in demanding marine conditions, from corrosion resistance to temperature cycling performance.</p><h3>Instrumentation and Monitoring Systems</h3><p>Accurate instrumentation is essential for boat operators to monitor engine health and prevent costly breakdowns on the water. Sierra's comprehensive line of <a href="/7570-sierra-gauges-200483">gauges</a> includes everything from fuel pressure and temperature indicators to voltmeters and trim gauges, all designed with marine-grade materials that withstand vibration, moisture, and UV exposure. Their <a href="/7570-sierra-tachometer-gauge-1488">tachometer gauges</a> deliver precise RPM readings critical for optimizing engine performance and fuel efficiency. Supporting these instruments, Sierra's <a href="/7570-sierra-gauge-resistor-47908">gauge resistors</a> ensure proper signal conditioning and accurate readings across various sensor types and engine configurations.</p><h3>Expanded Product Portfolio</h3><p>In 2022, Sierra significantly broadened its scope beyond traditional marine engine parts to encompass a wider range of boating accessories and even outdoor power equipment components. This strategic expansion brought established marine brands like Shields and Moeller under the Sierra umbrella, creating a one-stop resource for marine maintenance and replacement parts. The company now offers fuel systems, electrical components, battery charging solutions, and NMEA electronics alongside their traditional engine parts lineup.</p><h3>Quality Backed by Industry-Leading Warranties</h3><p>What sets Sierra apart in the crowded aftermarket marine parts market is their commitment to standing behind every component they manufacture. Their warranty coverage extends beyond simple part replacement—it includes shop labor, haul-out fees, towing charges, and related incidental costs should a warrantied part fail. This comprehensive protection reflects the company's confidence in their manufacturing processes and quality control standards. For boat owners facing repairs far from shore or mechanics working on customer vessels, this peace of mind is invaluable. Whether you're maintaining an outboard motor, rebuilding an inboard engine, or upgrading your boat's instrumentation, Sierra's decades of marine industry experience and commitment to quality make them a reliable choice for keeping your vessel running at peak performance.</p>

Part Number

18-99415
08/27/2036 2:54 PM
Sale Price

$146.80

1 left at this price

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Usually delivered within 2 days

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No Hassle Returns

Live-in-stock inventory

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Fitment guaranteed

Fitment guaranteed

Product Details

The Sierra 18-99415 is a CDM short arm ignition trigger designed as a direct replacement for Mercury and Mariner 4-cylinder 2-stroke looper outboard engines. The CDM (Capacitor Discharge Module) trigger is a critical ignition system component responsible for signaling the CDM power pack to fire at precisely the correct moment, ensuring reliable engine starting and smooth operation.

Key Features:

  • Short arm design engineered specifically for 4-cylinder 2-stroke looper engines with a 3.500" bore
  • Meets or exceeds OEM specifications for reliable, long-lasting ignition performance
  • Direct replacement for multiple Mercury and Mariner OEM part numbers
  • Backed by Sierra's limited lifetime warranty
  • Serial number range: 0G438000 – 1B000001

Replaces OEM Part Numbers:

  • Mercury: 834821, 834821T
  • Mercury: 854513T
  • Mercury: 855746A2, 855746A21
  • Mercury: 855748A2
  • CDI Electronics: 134-4513-4

Sierra Marine, now merged with CDI Electronics, is a trusted leader in marine ignition components. The 18-99415 trigger is a proven aftermarket solution for restoring proper ignition timing and spark on Mercury and Mariner looper outboards.

Timeley shipping of product.

Price was spot on and shipping was very fast! Highly recommend THMotorsports and will be checking to shop with them again!

The only issue was the shipping straps on both shocks were broken on one end only! Made it more difficult to install! But for the price I can't complain much! Thanks

Shopping took longer than I thought

The expierience has been great, would purchase from them again.

good price

Good product and price

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