Sierra Wire Coil 18-99172 Ignition Coil for Johnson Outboard Engines

The Sierra Wire Coil, part number 18-99172, is an ignition coil built for Johnson outboard engines. It is designed as a direct component replacement within the ignition system, supplying the spark energy needed for reliable engine starting and running performance. The coil is a compact, lightweight component intended to be installed as part of routine ignition maintenance or when diagnosing a no-spark or weak-spark condition on a Johnson outboard.

Ignition coils are a common wear item on outboard engines, and replacing a failing coil with a properly specified part like the Sierra 18-99172 helps restore consistent ignition timing and engine reliability. This coil is sold as a standalone wire coil unit for straightforward installation into the existing ignition harness.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-99172
• Product Type: Wire Coil (Ignition Coil)
• Application: Johnson Outboard Ignition
• Weight: 0.04 pounds

Fitment

Designed for Johnson outboard engines.

Replaces (OEM)

No OEM cross-reference numbers are specified for this part.

Frequently Asked Questions

What is the Sierra 18-99172? It is a wire coil, an ignition coil built for Johnson outboard engines, identified by Sierra part number 18-99172.

Will this coil fit my Johnson outboard? The Sierra 18-99172 is designed for use in Johnson outboard ignition systems; check that your engine's ignition coil matches this part number or its listed application before ordering.

How much does the Sierra 18-99172 weigh? This ignition coil weighs 0.04 pounds.

Is the Sierra 18-99172 a genuine Sierra part or aftermarket? The 18-99172 is sold under the Sierra brand as part number 18-99172, manufactured to serve as an ignition coil for Johnson outboard engines.

What does an ignition coil do on an outboard engine? An ignition coil, such as the Sierra 18-99172, stores and delivers the electrical energy needed to generate a spark for combustion in the engine's ignition system.

Are there OEM cross-reference numbers for the 18-99172? No OEM cross-reference or replacement numbers are specified for the Sierra 18-99172 wire coil.

What is included when I order the 18-99172? Ordering the Sierra 18-99172 includes one wire coil unit for installation in a Johnson outboard ignition system.

When should I replace my outboard's ignition coil? An ignition coil like the Sierra 18-99172 typically needs replacement when an engine shows symptoms of weak spark, misfiring, or failure to start, which are common signs of ignition coil wear.

Is the Sierra 18-99172 a direct replacement part? Yes, the 18-99172 is designed as a wire coil replacement for the ignition system on applicable Johnson outboard engines.

What category of part is the 18-99172? The 18-99172 falls under Johnson outboard ignition coils, specifically categorized as a wire coil.